Of all cases of Cold War conflict in
which the United States could have used nuclear weapons, the Vietnam War
provides one of the strongest “tests” of a taboo against their first use. In Vietnam, the United States chose to lose
a humiliating and destructive war against a small, nonnuclear adversary while
all its nuclear weapons remained on the shelf.
During the ten year military commitment to South Vietnam in the 1960s
and 1970s, the United States sustained large losses in men, money and materiel
at tremendous political cost. U.S.
officials repeatedly declared that the United States could not tolerate the
loss of Southeast Asia to communism, and that the war was vital for U.S.
interests, prestige, and security.
As the war escalated, the United
States was willing to maintain policies of great destructiveness. Operation Rolling Thunder, begun in March
1965, continued for three years and dropped more bombs on Vietnam than had been
dropped on all of Europe in WWII. Starting in 1969, B-52 raids demolished vast
areas in North and South Vietnam, Cambodia and Laos. U.S. forces employed herbicides and defoliants to obliterate
croplands and forests, dropped flame throwers and napalm, and eventually mined
Haiphong harbor. It is estimated that
some 3.6 million Vietnamese, both North and South, were killed in the conflict,
and 58,000 Americans.
The Vietnam War also makes a good
case for exploring the role of a taboo because of a widely perceived analogy to
the Korean War among U.S. decisionmakers at the time. In Korea the United States had demonstrated
that, despite its virtual nuclear monopoly, a nuclear power could engage in a
“limited,” nonnuclear war. However,
because of the perceived military and political costs of that war for the
United States, after Korea a great deal of debate took place as to the
feasibility and desirability of fighting another such limited war in the same
way. One popular lesson the Army (along with some
political leaders) learned from the Korean stalemate was “never again a land
war in Asia,” whose real meaning, administration insiders with access to
military planning understood, was “never again a land war against China without
nuclear weapons.” Doctrines of limited nuclear war developed
in the mid-to-late 1950s and early 1960s elaborated the necessity of being
willing and able to employ nuclear weapons in a local or regional conflict, and
in something less than an all-out nuclear exchange.
Had U.S. leaders wished to use
nuclear weapons in Vietnam, there was no lack of warheads nor any shortage of
suitable targets. Ports, landing
places, supply lines, bridges, railways and airfields could all have been hit
decisively with relatively low-yield weapons.
As McGeorge Bundy, national security adviser to presidents Kennedy and
Johnson, later observed, such targets could have been hit with nuclear weapons
“quite possibly with human losses lower than those of the war that was actually
fought.” Further, fear of nuclear retaliation was not
a prominent concern. Bundy recalled,
“Very little, if at all, was [the nonuse of nuclear weapons] for fear that
friends of [North] Vietnam with warheads of their own, Russians or Chinese,
would use some of them in reply.”
Given this context, one of the
remarkable features of the Vietnam War is how little serious thought U.S.
leaders gave to the possibility of using nuclear weapons. Despite the commitment to avoiding defeat,
the prevailing theories of limited nuclear war, and the levels of destruction
wrought upon Vietnam by conventional means, U.S. political and military leaders
never really came close to using nuclear weapons in the conflict. Presidents Kennedy and Johnson gave little
serious consideration to nuclear options and declined to make any nuclear
threats, despite some recommendations to do so. While President Nixon and his national security adviser Henry
Kissinger more actively explored nuclear options, and engaged in vague nuclear
threats, in the end they also did not come close to actually using such weapons
in the conflict.
Still, they were not quite as much
of a non-issue as Bundy portrayed in his majesterial history of nuclear
decisionmaking. In reality, they were an ongoing subtext of
a war that took place in a Cold War context.
The possibility of employing nuclear weapons was discussed in various
meetings of high-level officials before the first major American troop
deployments in March 1965 and at sporadic intervals up through 1972. Both military and political leaders thought
that tactical nuclear weapons would be militarily useful, and even necessary,
if the conflict expanded, and U.S. leaders received recommendations to use them
or threaten to use them from reputable individuals, including Bundy
himself. Also, Nixon and Kissinger
thought about it themselves. The
possible use of tactical nuclear weapons in the war was the occasional subject
of public rumor and speculation, and emerged as an issue in the presidential
campaigns of 1964 and 1968.
Why did U.S. leaders not resort to
use of tactical nuclear weapons to avoid a frustrating defeat and perhaps
shorten the war and save American lives and treasure? Fear of uncontrolled escalation to war with Russia or China is an
important part of the explanation.
However, such risks were highly disputed throughout the war, and
military and most key political leaders endorsed policies that involved risking
war with China if necessary. Given this
situation, political and normative constraints on the use of nuclear weapons
became particularly salient.
Ultimately, while nuclear weapons might have been militarily useful in
the war, it was clear that, by the time the war was fought, they were politically unusable, and for some
officials, even morally unacceptable.
The constraining and constitutive effects of a taboo against first use
of nuclear weapons operated powerfully for U.S. leaders during the Vietnam War,
both for the majority who shared the taboo and for the minority of those who
did not.
Return to Top
The
Johnson Administration and Vietnam
In 1961 President Kennedy had
rejected intervening in the Laos crisis—defying the recommendations of most of
his advisers in doing so---as soon as he realized that U.S. troops would
inevitably be outnumbered on the ground and that U.S. military chiefs would
count on nuclear weapons to redress the balance. The issue of nuclear weapons arose again
under President Johnson in the context of the decision of 1964-65 to intervene
militarily in Vietnam, which culminated in the Rolling Thunder bombing campaign
and the first major introduction of U.S. troops in March 1965. Once the United States had committed troops
to the defense of South Vietnam, the Joint Chiefs of Staff regularly pushed for
major expansions of the war, including nuclear options. The Johnson administration’s most extensive
discussions of nuclear weapons took place during the 1968 siege of Khe Sanh,
but even this did not get far. There
were two sustained critiques of the use of tactical nuclear weapons in the
conflict: Undersecretary of State
George Ball’s famous October 1964 memo, and a recently declassified study
conducted by physicist Freeman Dyson and three other scientists in 1966. Both of these papers came down strongly
against the use of nuclear weapons in the war.
Return to Top
Main
Scenarios for Use of Nuclear Weapons
The main scenario for resort to
nuclear weapons was a major ground war against Chinese and North Vietnamese
troops, although other options were occasionally proposed. Both military and political leaders thought
that use of tactical nuclear weapons in such a war would be likely, and
possibly even required, to avoid defeat.
Although military commanders were at times divided over whether nuclear
weapons would be needed in a wider war, the Joint Chiefs did estimate that
tactical nuclear weapons would be militarily useful, arguing in a memo in March
1964 that “nuclear attacks would have a far greater probability“ of stopping a
Chinese attack than responding with conventional weapons. As a JCS working group put it, “Certainly no
responsible person proposes to go about such a war [against the North
Vietnamese and Chinese], if it should occur, on a basis remotely resembling
Korea. ‘Possibly even the use of
nuclear weapons at some point’ is of course why we spend billions to have
them.” The Joint Chiefs essentially assumed that
Eisenhower era policies remained in force—that the United States had undertaken
to defend many areas on the assumption that nuclear weapons would be used as
necessary and that they would be effective.
Military leaders were unsure, for
example, whether conventional bombing of Chinese supply lines in North Vietnam
would be sufficient and assumed that at least ground forces, and possibly
nuclear weapons, would be required.
Admiral Harry D. Felt, Commander in Chief, Pacific (CINCPAC) believed
that in the event of a major ground war, there was no possible way to hold off
Communist forces on the ground without the use of tactical nuclear weapons, and
that it was essential that U.S. commanders be given the freedom to use them as
the contingency plans assumed. Chair of
the Joint Chiefs General Earle Wheeler opposed using nuclear weapons to interdict
supply lines but thought they would be necessary in a major war against China,
and should be used only in extreme cases such as to save a force threatened
with destruction or to knock out a special target like a nuclear weapons
facility. However, General Maxwell Taylor, who had
served as chairman of the Joint Chiefs and for a while as U.S. ambassador to
South Vietnam, was more doubtful about the need for nuclear weapons.
Top political leaders did go as far
as the Joint Chiefs. But during their deliberations
in 1964-65 over whether to intervene in the war, they raised the issue of
nuclear weapons, and seemed prepared to accept that they must be ready for
their use. The U.S. Ambassador to South
Vietnam, Henry Cabot Lodge, during meetings in April and May 1964, raised the
question of whether nuclear weapons would be needed to defend South
Vietnam. In a meeting on April 27,
Secretary of State Dean Rusk expressed concern about whether this would bring
the Soviets in, and also noted that he had been much struck “by Chiang
Kai-Shek’s strongly expressed opposition to the use of nuclear weapons.” William Bundy, Assistant Secretary of State
for the Far East, suggested that “limited use of such weapons for interdiction,
in unpopulated areas, might be a different story.” Rusk appeared doubtful that
this could be effective, although he allowed that some sort of threats might be
useful.
In November 1964, shortly after
Johnson was reelected president, an interagency task force chaired by William
Bundy was formed to analyze major courses of action for the United States in
Vietnam. In written comments on the
draft papers laying out three options, A, B and C, Bundy asked with regard to
Option B, the most aggressive course of action, “At what stage, if ever, might
nuclear weapons be required, and on what scale? What would be the implications of such use?” He commented, “This is clearly a sensitive
issue. The President may want a more
precise answer than appears in the papers.”
On November 23, the JCS, in a memo
to Secretary of Defense Robert McNamara, criticized option A as inadequate, and
offered their own versions of options B and C which would include “an advance
decision to continue military pressures, if necessary, to the full limits of
what military actions can contribute toward U.S. national objectives.” In the context, the reference to nuclear
weapons was unmistakable. The Chiefs
had argued earlier, on November 10, that the risk of nuclear conflict should
deter Chinese communist intervention, while expressing a clear willingness to
use nuclear weapons should the Chinese intervene.
During
the meeting of the Executive Committee (ExCom) of the NSC on November 24 to
discuss the three options, someone asked whether nuclear weapons might be
used. McNamara said he “could not
imagine a case where they would be considered,” but McGeorge Bundy thought that
under certain circumstances there might be political and military pressure to
consider their use. However, no precise answer was forthcoming,
and the Pentagon Papers narrative
notes after one such inconclusive mention of nuclear weapons that “again, the
point was not really followed up.” The ExCom eventually chose option C’, the
Chiefs’ plan, with some modifications.
The final December 2 draft of the paper (approved by Johnson on December
7) incorporated the Chiefs’ call for aggressive countermoves to North
Vietnamese escalation, but emphasized troop deployments and did not incorporate
the JCS language committing the United States to the full range of military
actions.
While no
nuclear weapons were deployed in Vietnam, they were on board aircraft carriers
and stockpiled in the region, increasing in numbers up through mid-1967. CINCPAC plans for a major escalation of the
war included both nuclear and nonnuclear options. Recently declassified Pacific Command histories confirm the
existence of these nuclear war plans, first revealed in the Pentagon Papers. A U.S. response to Chinese intervention into
hostilities would require implementation of CINCPAC OPLAN 39-65 and/or OPLAN
32-64. In the event of Chinese entry
into the war, Strategic Air Command (SAC) forces would strike selected targets
within China using nuclear and/or nonnuclear weapons, as directed by the JCS. Additionally, when American Marines
arrived in Da Nang in March 1965, they brought eight-inch howitzers that were
nuclear-capable, though they did not have nuclear warheads. It would thus have been relatively easy for
the United States to change the character of the war to a nuclear one.
There were several constraints on
using nuclear weapons, however, including the risk of escalation, political
costs, and moral considerations.
Return to Top
Uncertain Escalation Risks
The most significant material constraint on
using nuclear weapons was the risk of a wider war with China. U.S. leaders worried that a U.S. invasion of
North Vietnam or the use of tactical nuclear weapons there could bring China
into the war. Winning a war against
China might itself require use of nuclear weapons. In a remote but worst-case scenario, this could provoke Soviet
entry into the war, although most U.S. officials judged this unlikely. Thus the United States might be forced to
use nuclear weapons first, with unpredictable, and possibly disastrous,
consequences.
However, political and military
leaders disagreed bitterly over such escalation risks throughout the war. The JCS tended to see them as much lower
than did political leaders, and hence were more willing to endorse aggressive
policies. The Chiefs, along with
commanders in the field, consistently lobbied for expanding the war and
removing limitations on the fighting as the only way to achieve victory. On January 22, 1964, they told McNamara that
the United States “must be prepared to put aside many of the self-imposed
restrictions which now limit our effectiveness, and to undertake bolder actions
which may embody greater risks.” They advocated a vigorous bombing campaign
against North Vietnam and the introduction of U.S. combat forces in both North
and South Vietnam. In response,
McNamara directed them to plan a campaign of covert actions and air and sea
attacks on North Vietnam up to but not including nuclear weapons. The JCS then complained that if China
entered the war nuclear weapons might be needed, and submitted a plan
culminating in a strike at the Chinese atomic production facility that would
produce a bomb in October 1964.
McNamara took a similar aggressive stance on this initially, but then
scaled it back before presenting it to the President.
Former president Eisenhower, called
in for a consultation on Vietnam in February 1965, shortly before the final
decision supporting the first major deployment of American troops, found the
nuclear option entirely reasonable. He
told President Johnson and senior advisers that he thought the Chinese would
not enter the war, but if they did he would use “any weapons required,”
including nuclear weapons if necessary.
He recommended using carrier-based tactical nuclear weapons for “instant
retaliation,” suggesting that they could be used on large troop formations and
supply depots. In his view, this
would not increase the chances of escalation.
Emphasizing the utility of deterrent threats, he recommended threatening
China with nuclear weapons.
Further, as he had done in the
Korean War, he explicitly advocated challenging the taboo on the first use of
nuclear weapons. The United States, he
said, should not be bound by the restrictions of the Korean War, including the
“gentleman’s agreement” on not using nuclear weapons. This would keep the Chinese out of the war. This view was shared by South Vietnamese
leader General Nguyen Khanh, who had told Rusk during Rusk’s visit to southeast
Asia in April 1964 that as far as he was concerned the United States could use
anything it wanted against China. Eager to expand the war to the North, Khanh
had no objections to use of nuclear weapons, noting on another occasion that
decisive use of atomic bombs on Japan had saved not only American but also
Japanese lives.
Eisenhower’s
statements suggest that he, like the JCS, perceived few material constraints on
the use of nuclear weapons––he believed that nuclear weapons would be useful on
the battlefield, saw minimal escalation risks, and demonstrated no evident
concern about long term consequences of their use. He uttered no cautionary words of any kind to Johnson and his
advisers. In his view, the main
constraint on use of nuclear weapons was a political-normative one––the
“gentleman’s agreement”––which he advocated breaking. It might be argued that he was an aging general no longer in the
loop, but his statements are entirely consistent with those he made when he was
president.
Secretary
of State Rusk endorsed Eisenhower’s recommendations to institute a “campaign of
pressure” against North Vietnam, although he did not share Eisenhower’s views
on nuclear weapons. In a strong
personal memo to the President shortly after the meeting with Eisenhower, he
wrote, “Everything possible should be done to throw back the Hanoi-Viet Cong
aggression––even at the risk of major escalation.”
At an NSC meeting in May 1964, Rusk had suggested moving a U.S. division in
Korea to Southeast Asia, and making a public declaration that any attack on
South Korea would be met by the use of nuclear weapons. He believed that if escalation brought about
a major Chinese attack, it would also involve use of nuclear arms, a risk he
was willing to take. But like the
military, Rusk thought the escalation risks were low. He thought that the Chinese leaders were “practical men” who
would act prudently, in part because of the U.S. nuclear arsenal. As he noted to the Romanian foreign minister
in October 1965, “After all, Chinese nuclear capability within the foreseeable
future will always be trivial as compared to that of the U.S.” Nevertheless, Rusk vigorously opposed
bombing near the Chinese border, and, although he found some use for nuclear
threats, unlike Eisenhower, did not actually advocate use of nuclear weapons.
The military’s benign views of the
escalation risks were especially alarming to Undersecretary of State George
Ball, who worried about a protracted ground war with China, which might produce
substantial U.S. casualties. As he
wrote in a famous skeptical memo on U.S. conduct of the war to McNamara, Bundy,
and Rusk in October 1964, “At this point, we should certainly expect mounting
pressure for the use of at least tactical nuclear weapons. The American people would not again accept
the frustrations and anxieties that resulted from our abstention from nuclear
combat in Korea.” Ball worried that the
fact that there was no longer any shortage of suitable nuclear warheads removed
an important material constraint on their
use. “The
rationalization of a departure from the self-denying
ordinance of Korea would be that we did not have battlefield nuclear
weapons in 1950––yet we do have them today.” Given a situation of nuclear plenitude, and
the military’s benign assessment of the consequences of a wider war or using
nuclear weapons, Ball worried that there were few military or material
constraints on the military’s analysis of nuclear options.
Ball and others sensitive to
escalation risks also worried about the uncertain Soviet reaction to a U.S. use
of nuclear weapons. He wrote in his
October 1964 memo, “While one cannot be certain, the best judgment is that the
Soviet Union could not sit by and let nuclear weapons be used against China.” Similarly, in a lengthy memo to Johnson on
the same day as the meeting with Eisenhower, Vice President Hubert Humphrey,
who opposed the 1965 decision to expand the war, cautioned that if a war with
China had been ruled out in 1952-53 when only the United States had a usable
nuclear capability, it would be even harder to justify such a war now. “No one really believes the Soviet Union
would allow us to destroy Communist China with nuclear weapons, as Russia’s
status as a world power would be undermined if she did.” At the Honolulu conference on June 2, 1964,
Rusk had also noted the risk of provoking a nuclear exchange with the Soviets,
“with all that this involved.”
Nevertheless, unlike in previous Cold War crises, during the
Vietnam conflict U.S. military leaders did not think war with the Soviet Union
was imminent, and were not deterred in their conduct of the war by fear of
Soviet entry into the hostilities. This
was due to the Sino-Soviet split and the highly public animosity between the
two communist great powers by the mid-1960s, along with the relative “detente”
between the United States and the Soviet Union in the wake of the 1962 Cuban
missile crisis. Official U.S.
intelligence estimates consistently stated that it was unlikely either China or
the Soviet Union would intervene unless the United States invaded North Vietnam
with a massive show of troops, bombed China, or attacked Soviet supply ships in
Haiphong harbor. A Special National
Intelligence Estimate of October 9, 1964 stated that “We are almost certain
that both Hanoi and Peiping are anxious not to become involved in the kind of
war in which the great weight of US weaponry could be brought to bear against
them. Even if Hanoi and Peiping
estimated that the US would not use nuclear weapons against them, they could
not be sure of this....”
By mid-1965 the administration was
convinced that the Soviet Union’s commitment to long-term improvement of
relations with the West took precedence over its support for North
Vietnam. In spring 1965, after
operation Rolling Thunder had begun, Chinese leader Zhou Enlai signaled to
Washington through the Pakistanis and the British that Chinese forces would not
become involved militarily in Vietnam if the United States refrained from
invading North Vietnam or China and did not bomb the North’s Red River dikes. However, should war break out, even nuclear
weapons would not force them to quit, and the war would have no boundaries.
However, President Johnson was
determined, even obsessed, with keeping the war restrained, a view shared by
McNamara and others, who thought that even if the actual risks of a wider war
were low, the consequences were unacceptable.
The problem was the risk of uncontrolled escalation, which could lead to
possibly catastrophic outcomes. Johnson
and his advisers, veterans of the 1962 Cuban missile crisis, were committed to
limiting as much as possible the geographical area of the conflict and the
volume of force used. Johnson, in
particular, was “haunted by the ceaseless fear” of Soviet and Chinese
intervention.
Still, although escalation concerns played a
role, they were far from determining.
While national leaders clearly wanted to avoid escalation that might
lead to a large conventional or nuclear war, top political and military
officials disagreed strongly over the risks and consequences of escalation. In practice, the fear of defeat in Vietnam
repeatedly made significant risks of escalation acceptable. On February 9, 1965, McGeorge Bundy wrote
Senator Mike Mansfield that the administration was willing to run the risk of
war with China, and implied a willingness to make a sacrifice at least equal to
that of the Korean War. Although
top civilian leaders did not advocate or support use of nuclear weapons,
and although McNamara later remembered himself appalled by the JCS position on
nuclear weapons, at times during 1964-65, comments by him and other civilian
leaders showed a willingness to run risks that might have led to nuclear war
against China, much as the Chiefs were advocating.
Return to Top
Political and Normative Concerns
In the face of uncertainty and disagreement over escalation risks,
political and normative concerns about using nuclear weapons may have become
particularly salient, if not decisive, for many top officials. As in Korea, U.S. leaders worried that,
given world public abhorrence of nuclear weapons––now even stronger than in the
1950s––the use of such weapons in the Vietnam conflict would jeopardize the
U.S. moral and leadership position in the eyes of friends and allies,
especially if the United States used them again on Asians. In a memo to President Johnson,
Undersecretary Ball wrote: “To use
nuclear weapons against the Chinese would obviously raise the most profound
political problems. Not only would
their use generate probably irresistable pressures for a major Soviet involvement,
but the United States would be vulnerable to the charge that it was willing to
use nuclear weapons against non-whites only.”
Indeed, foreign leaders privately and
publicly cautioned against use of nuclear weapons. Chiang Kai Shek, leader of
nationalist China, told Rusk during Rusk’s trip to southeast Asia in April 1964
that he was “opposed in principle” to use of nuclear weapons, “particularly in
settling the China problem.” Returning to Washington, Rusk reported to
the NSC that he had been impressed by Chiang’s “passionate statement” that
“nuclear war in Asia would be wrong.” Chiang’s opposition to use of nuclear
weapons undoubtedly stemmed in part from his concern that Taiwan would be the
most likely object of a Chinese counterattack, probably overwhelming, and
Chiang and his regime would be at risk.
A month later, in Honolulu, Rusk noted that “many free world leaders
would oppose this [use of nuclear weapons].” When the French ambassador to Washington
suggested to Rusk in July 1964 that a nuclear threat might have a “most
sobering effect” on the Chinese, Rusk again responded that Asians, including
“even Chiang Kai Shek, ”were strongly opposed to use of nuclear weapons in
Asia.
Other foreign leaders urging restraint including U Thant, Secretary-General of
the UN, Prime Minister Lester Pearson of Canada, and British prime minister
Harold Wilson. Mounting public opposition to the war gave
U.S. leaders a demoralizing foretaste of the kind of world public outrage that
a use of nuclear weapons might provoke.
But
it was not only the concerns and abhorrence of others that played a role. A nuclear taboo was becoming entrenched
among high officials of the Kennedy and Johnson administrations. President Johnson, especially, was obsessed
with limiting the war. Like Truman
during the Korean War, he abhorred the thought that he might ever have to
consider use of nuclear weapons. His
memoirs make no mention of nuclear weapons being considered in Vietnam. His senior advisers have testified strongly
that by as early as 1964 Johnson was clear in his own mind that he would not
order a first use of nuclear weapons except perhaps in the case of overwhelming
Soviet aggression in Europe. He never
raised with these advisers the question of how far the American people would
support a decision to use the bomb in Vietnam.
Johnson had spoken out strongly
during the 1964 presidential campaign when Senator Barry Goldwater, campaigning
for the Republican presidential nomination in May 1964, suggested in a speech
that tactical nuclear weapons should be treated more like conventional weapons,
and that they should be used in Vietnam.
The previous October, Goldwater had recommended delegating
responsibility for decisions on use of nuclear weapons to military commanders
in the field under some circumstances (Johnson, continuing Eisenhower policies,
had delegated some authority but only under very limited circumstances). In a speech in Detroit on Labor Day, 1964,
Johnson came out strongly against Goldwater’s views. He described the catastrophe of nuclear war and said, “Make no
mistake. There is no such thing as a
conventional nuclear weapon.” He
continued:
For 19
peril-filled years no nation has loosed the atom against another. To do so now is a political decision of the
highest order. And it would lead us
down an uncertain path of blows and counterblows whose outcome none may
know. No President of the United States
can divest himself of the responsibility for such a decision.
The
reference to “19 peril-filled years” is a strong one, and Johnson’s statement
emphasizes both the “tradition of nonuse” and the fear of uncontrollable
escalation. Bundy wrote later that
although there was politics in Johnson’s speech, there was “passionate conviction”
as well. Two factors appeared to be key in Johnson’s
thinking: the long term effect of any
use of the bomb “on the survival of man”––a prudential consideration, and the
desire not to be the first president in twenty years to use nuclear weapons, that
is, to break the powerful “tradition” of nonuse that had now developed––a taboo
consideration. Johnson did not want to
be the president who set the precedent for use of nuclear weapons. For him, it appears, the use of the bomb in
Vietnam was quite literally “unthinkable.”
Many of Johnson’s
advisers––especially Robert McNamara and Dean Rusk––already possessed a set of
strongly held beliefs about nuclear weapons by this point in time. Cold War crises over Berlin and Laos (1961)
and Soviet missiles in Cuba (1962) had already forced them to confront the
possibility of using nuclear weapons.
Appalled by the Eisenhower nuclear doctrine of “massive retaliation,”
Kennedy and his advisers had sought more “flexible” war plans that included
greater emphasis on conventional weapons.
Further, in the early 1960s, an emerging debate among the fledgling
group of civilian arms control analysts on the merits of a “no first use”
policy began to challenge the logic of the prevailing U.S. deterrence policy
based on the threat to use nuclear weapons first.
Under McNamara the Pentagon began to
revise Eisenhower’s Basic National Security Policy (BNSP), but the process
bogged down in several dilemmas, one of which was the puzzling question of
when, if at all, tactical nuclear weapons might be used. It was one of several reasons why there was
never a final agreed BNSP for the Kennedy administration. Walt Rostow, a hawk who took over the process
of revising the plan when he became head of Policy Planning in the State Department
in 1962, found the role of tactical nuclear weapons “a tough nut to
crack.” It remained an unresolved
dilemma because of “differences of view in the Pentagon.” Thus the draft BNSP was simply left with a
statement of the dilemma posed by tactical nuclear weapons: they were extremely important as a deterrent
against massive conventional attack in Europe and elsewhere, but their actual
use could produce civil and human destruction on a vast scale, in some cases
(depending on locale) tantamount to the strategic use of nuclear weapons.
The growing opposition to the policy
of use of tactical nuclear weapons significantly reflected McNamara’s personal
views. From early in his tenure as
secretary of defense, McNamara opposed use of nuclear weapons, viewing them as
morally objectionable and lacking in utility, issues he often ran
together. He had been horrified by the
briefing he received in early February 1961, only two weeks in office, from
General Thomas Power, commander of the Strategic Air Command (SAC), on SIOP-62,
the U.S. plan for nuclear war inherited from the Eisenhower
administration. It called for an
all-out preemptive first strike on the Soviet Union, Eastern Europe and China,
involving a million times as much explosive power as used in Hiroshima, in
response to an actual or merely impending invasion of Europe by the Soviet
Union that involved no nuclear weapons at all. Millions of Chinese would be destroyed for
no obvious reason. Returning to
Washington, McNamara ordered a review of the nuclear stockpile, which
eventually resulted in a unilateral 50% cut in stockpile megatonnage. He also ordered an increase in nonnuclear
capabilities for countering conventional aggression so that the United States
would not be forced to rely on tactical nuclear weapons.
McNamara apparently decided very
early on that the United States should never strike first with nuclear
weapons. This was made clear in policy
documents he sent to the JCS chairman shortly after the war plan briefing that
so disturbed him. He has stated frequently that he privately
advised both Kennedy and Johnson never to initiate the use of nuclear weapons,
and they agreed.
Daniel Ellsberg, a Pentagon planner
who disagreed with McNamara’s strong advocacy of bombing North Vietnam, and who
later became famous for leaking the Pentagon Papers to the press,
nevertheless felt that McNamara shared his strong personal abhorrence of
nuclear weapons. Recalling a private
meeting with McNamara in 1961 in which McNamara spoke with “great passion”
about the dangers of nuclear weapons and U.S. nuclear war plans, Ellsberg wrote
that “he impressed me strongly and positively that day with his conviction that
under no circumstances must there be a first use of U.S. nuclear weapons in
Europe.” He added, “I’ve never had a
stronger sense in another person of a kindred awareness of this situation and
of the intensity of his concern to change it.” After the meeting, McNamara’s assistant told
Ellsberg that Johnson’s thinking on this subject was “not one iota” different
from McNamara’s. This meeting took place even before the 1962
Cuban missile crisis, an event which drove home to McNamara the dangers of
uncontrolled escalation.
Like McNamara, Dean Rusk, Secretary
of State to both Kennedy and Johnson, found nuclear weapons abhorrent. With a background in international law, he
took a strongly principled approach to diplomacy and America’s role in the
world. George Ball, who disagreed with
Rusk’s fairly aggressive views on the war, nevertheless described him as a man
of “extraordinary integrity and selflessness.” According to Rusk, “we never seriously
considered using nuclear weapons in Vietnam.”
He advocated aggressive uses of force but opposed use of nuclear weapons
in Vietnam and elsewhere because of fallout risks, political costs, lack of
good targets in Vietnam, adequate conventional alternatives, but especially
because of the unacceptable killing of civilians. It is clear that Rusk had been impressed by
the opposition to use of nuclear weapons he had encountered during his trips to
Asia. He noted that many Asians seemed
to see an element of racial discrimination in use of nuclear arms. Was it something the United States would do
to Asians but not to Westerners? He wrote later, “Under no circumstances
would I have participated in an order to launch a [nuclear] first strike, with
the possible exception of a massive [Soviet] conventional attack on West
Europe," which he thought unlikely. “The only rational purpose of nuclear weapons is to ensure that no
one else will use them against us.”
These are remarkable admissions from
McNamara and Rusk. In effect, top U.S.
officials harbored private commitments to “no first use,” in part for moral
reasons, despite the fact that such views directly contradicted official U.S.
deterrence policy relying on a threat to initiate use of nuclear weapons. (They also contradicted U.S. plans for
limited war emphasizing first use of nuclear weapons in a conflict with large
Chinese forces in Asia). McGeorge Bundy
wrote later that he believed that McNamara and Rusk would have resigned if
President Johnson had asked for a decision to use the bomb in Vietnam, and that
Johnson “quietly appreciated this.”
Return to Top
The 1964 Ball Memo
The most systematic analysis of the
consequences of using nuclear weapons in Vietnam came from Undersecretary Ball
in his October 1964 memo. While he
again raised the risk of Soviet intervention following any use of nuclear
weapons, his primary emphasis was on the negative political consequences of any such use. The entire passage under the heading “Pressure for Use of Atomic Weapons,” more than a dozen
paragraphs, is devoted to assessing the political costs to U.S. leadership of
any use of the bomb. Nowhere here does
he mention either risks of nuclear retaliation or escalation to a wider war,
nor the military utility of nuclear weapons, which he appears to assume (by
contrast, when he does mention the risk of Soviet intervention in response to a
U.S. use of nuclear weapons, it is in one sentence in the subsequent section on
“Possibility of Soviet Intervention”).
In his analysis, Ball noted the lack
of meaningful distinction between tactical and strategic weapons in the eyes of
the public, and the “profound shock” that would follow any use of nuclear
weapons “not merely in Japan but also among the nonwhite nations on every
continent.” He predicted that “our loss
of prestige” in the non-aligned and less-developed countries would be
“enormously magnified if we were led to use even one nuclear weapon.”
Most significant, however, was an
analysis of the consequences of legitimizing use of nuclear weapons. Ball wrote that if the United States used
such weapons,
“...our
action would liberate the Soviet Union from the inhibitions that world
sentiment has imposed on it. It would
upset the fragile balance of terror on which much of the world has come to
depend for the maintenance of peace.
Whether or not the Soviet Union actually used nuclear weapons against
other nations, the very fact that we had provided a justification for their use
would create a new wave of fear....The Communists would certainly point out
that we were the only nation that had ever employed nuclear weapons in
anger. And the Soviet Union would
emphasize its position of relative virtue in having a nuclear arsenal which it
had never used.”
The consequences of this could not
be overstated, he wrote. The first use
of the bomb by the United States would set back all the progress made in
superpower relations over the previous few years. It would also generate domestic “resentment against a Government
that had gotten America in a position where we had again been forced to use
nuclear power to our own world discredit.”
Ball’s concern about the negative
precedent set by the use of even a single nuclear weapon was not primarily
because it would demonstrate that such weapons were militarily useful, or that
it would invite Soviet retaliation.
Rather, it would suggest that nuclear weapons were legitimate. If the U.S. resorted
to the bomb, the Soviet Union would then feel free to use it “against other
nations.” Legitimizing the use of
nuclear weapons would undermine a major normative inhibition on resorting to
them in war––a major stabilizing factor of successful nuclear deterrence (“the
balance of terror”). In other words, a
shared normative expectation of nonuse was an
essential element of, not an alternative to, stable nuclear
deterrence. Because of this, the
country that broke the tradition of nonuse of nuclear weapons would be
stigmatized as a pariah among nations.
Ball’s memo---or at least parts of
it---was not well-received. Rusk and
McNamara entirely rejected his questioning of the administration’s arguments
for conventional bombing of North Vietnam.
However, it is likely that they were quite sympathetic to his arguments
about nuclear weapons, which accorded substantially with their own views.
Return to Top
Nuclear
Bluffing
Still, there is some evidence that
U.S. officials were not totally averse to making nuclear threats. On
April 22, 1965, just after the first deployment of US troops to Vietnam, and as
the Johnson administration was shifting its focus to a greater effort to win
the ground war, McNamara gave a not-for-attribution briefing to reporters. After reviewing and defending U.S. strategy
in Vietnam, he introduced a new element—a nuclear bluff. A New York Times reporter recorded
his words:
We are NOT
following a strategy that recognizes any sanctuary or any weapons
restriction. But we would use
nuclear weapons only after fully applying non-nuclear arsenal. In other words, if 100 planes couldn’t take
out a target, we wouldn’t necessarily go to nuclear weapons; we would try 200
planes, and so on. But “inhibitions”
on using nuclear weapons are NOT
“overwhelming.” Conceded it would be a “gigantic step.” Quote:
“We’d use whatever weapons we felt necessary to achieve our objective,
recognizing that one must offset against the price”---and the price includes
all psychological, propaganda factors, etc.
Also fallout on innocents.
“Inconceivable” under current circumstances that nuclear would provide a
net gain against the terrific price that would be paid. NOT inconceivable that the price would be
paid in some future circumstances McNamara refuses to predict.”
These remarks created a flap when
they appeared in the newspapers on April 25, and McNamara amended his comments
publicly the next day. “There is no
military requirement for nuclear weapons” in the present and foreseeable
situation, he said, “and no useful purpose can be served by speculation on
remote contingencies.” Yet, as David Kaiser notes, his original
threat could not have been accidental.
While
Eisenhower remained the most steadfast advocate of the utility of nuclear
threats, even McGeorge Bundy toyed with the idea. In a memo to McNamara in June 1965 criticizing a vast increase in
American troops that McNamara was planning, Bundy noted Eisenhower’s nuclear
threats in the Korean War and suggested that the United States “should at least
consider what realistic threat of larger action is available to us for
communication to Hanoi.” He added, “A full interdiction of supplies to North
Vietnam by air and sea is a possible candidate for such an ultimatum. These are weapons which may be more useful
to us if we do not have to use them.” McNamara wrote later that he did not share
Bundy’s views on nuclear weapons and threatening their use, though he did on
everything else—a recollection that is somewhat inconsistent with his behavior
at the time. On December 2, 1965, McNamara referred in a
telephone conversation with Johnson to certain “very dangerous alternatives
that we can’t even put in writing around here, [and] certainly don’t want to
talk to anyone else about.”
The
nuclear bluff may have been what Bundy suggested---a strategy of communicating
seriousness to Hanoi and Moscow. Soviet
leaders indeed got word that U.S. officials were entertaining nuclear options,
a prospect they viewed with the greatest alarm. According to historian Ilya Gaiduk, drawing on newly available
Soviet documents, in summer 1965 Soviet leaders received regular reports that
the United States might resort to nuclear weapons to suppress the insurgency in
South Vietnam. In June 1965, Soviet
intelligence informed the Kremlin that in a conversation with Italian Foreign
Minister Amintore Fanfani, Rusk had admitted that the prospect of using
tactical nuclear weapons in Vietnam was on the agenda of American policymakers. Although it is unclear how reliable the
reporting was, or what exactly “on the agenda” meant, the report apparently
spurred Soviet leaders to consider seriously the question of U.S. readiness to
wage a nuclear war and the Johnson administration’s intentions in this regard. There thus appears to have been some pattern
of nuclear threatmaking, even if it was a bluff.
Return to Top
Taboo
Effects
The nuclear bluffs notwithstanding, it became increasingly clear
that, in contrast to Korea ten years earlier, use of nuclear weapons in Vietnam
was indeed increasingly “unthinkable.”The operation of a nuclear taboo was
visible in variety of ways.Political
leaders rebuffed in outrage overt attempts to erode the taboo, and resisted
even analyzing nuclear options.Such
developments reflected a mounting burden of proof for any use of such weapons.
Not only were top officials
privately opposed to use of nuclear weapons, but––consistent with taboo
thinking––even the mere analysis of such weapons in the de rigueur cost-benefit
fashion for which the Kennedy administration was famous was essentially
taboo. Samuel Cohen, a weapons
physicist at the RAND Corporation who had advocated use of tactical nuclear
weapons in the Korean War, and who was one of the rare enthusiasts for such an
option in the Vietnam War, ran up against the taboo mindset. As he recalled, “anyone in the Pentagon who
was caught thinking seriously of using nuclear weapons in this conflict would
find his neck in the wringer in short order.”
His formerly good relationship with Pentagon officials had plummeted
because of his pro-nuclear weapons views:
“When the Kennedy guys came in, my relationship with the Office of the
Secretary of Defense dropped off to approximately zero. Those in key positions....had no use for my
views.”
In Pentagon war games, such as one
held in September 1964, to determine whether conventional firepower alone would
stop a Chinese intervention in a war in Southeast Asia, the answer the game
produced was probably not. However,
only a minority of the war game’s American leadership voted to use nuclear
weapons to destroy Chinese nuclear production facilities and execute a general
nuclear attack on China.
One
overt challenge to the taboo was the earlier-mentioned attempt by Goldwater
during the 1964 presidential campaign to reintroduce the notion of
“conventional nuclear weapons”––the same notion that Eisenhower and Dulles had
sought unsuccessfully to promote ten years earlier. In May 1964, Goldwater argued publicly that nuclear weapons
should have been used at Dien Bien Phu to defoliate trees, and that, in similar
fashion, “low-yield atomic weapons” should be used as defoliants along South
Vietnam’s borders, along with an expanded conventional bombing campaign of
North Vietnam. The idea drew an
immediate blast from UN Secretary-General U Thant. The Johnson administration went after
Goldwater with devastating effect, running anti-Goldwater TV adds with
antinuclear themes. The Pentagon responded to “Goldwater’s
folly” by describing technical characteristics of nuclear weapons, arguing that
it was absurd to call them conventional weapons. Goldwater persisted that the army possessed very small nuclear
weapons with a fraction-of-a-kiloton blast.
But to no avail. Johnson
responded with his famous Labor Day speech that “there is no such thing as a
conventional nuclear weapon.” McNamara
wrote later of Goldwater, “His statement implied that he saw no real difference
between conventional weapons and nuclear weapons. He went so far as to suggest the president should instruct
commanders in Vietnam to use any weapons in our arsenal. I profoundly disagreed and said so.”
Goldwater’s statements endorsing the
legitimacy of nuclear weapons---like those of Eisenhower and Dulles
earlier---represented a public attempt to challenge the growing taboo on their
use by eroding the line between conventional and nuclear weapons. The strong government and public reaction
illustrated how anathema such a view was to most people. The Johnson administration used to the
controversy to political advantage, tapping into the public’s fear of nuclear
war. But its strong response also
served to reinforce and uphold the by-this time widely shared public sentiment
that nuclear weapons were not conventional weapons, and to reaffirm the
taboo. Goldwater’s comments contributed
significantly to his landslide defeat. By the mid-1960s, advocating use of nuclear
weapons in a campaign speech was beyond the bounds of acceptability for most
people.
Return to Top
Investigating and Challenging the Taboo
As
in Korea, those who disagreed with official policy thought that normative
concerns inhibited policymakers from thinking “rationally” about nuclear
options. Samuel Cohen, the RAND weapons
scientist, attempted in vain to interest Washington in the virtues of
“discriminate” nuclear weapons in Vietnam.
He recalled, “I put my mind to work on how nuclear weapons might be used
to thwart the Vietcong.” His account of his efforts to promote
tactical nuclear options during the war, as well as his analysis of
policymakers’ and scientists’ resistance to this option, provide a fascinating
window into the operation of the taboo.
As he recalled later, during a
presentation on tactical nuclear weapons he gave to key planners in the State
Department in 1965, it quickly became evident that however intrigued his
audience was from a technical point of view, they were “adamantly opposed to
the development and use of such weapons from a political point of view.” During
the course of the talk he described several hypothetical weapon systems in
which low-yield nuclear weapons would be used to propel metal projectiles or
massive conventional weapons payloads.
In one example, the nuclear explosion would take place over the
battlefield but would give “only conventional effects on the target.” He expected that there might be some
interest in these options, which he argued were more effective and
discriminating than standard high explosive attacks. Instead, “the opposition remained unanimous, for the simple
reason that it was not really the nature of the effects that counted. Rather, it was the fact that a nuclear
explosion was taking place over the area of theater operations.”
Intrigued with the anti-nuclear
sentiment, Cohen now attempted to discern how deep it was. He described another hypothetical device, a
giant nuclear explosive cannon where very low-yield explosives could shoot
massive conventional payloads over many hundreds of miles. The military effects of the weapon––purely
conventional––would be felt only on the battlefield, while the source of
energy––nuclear––required to deliver these weapons would be well outside the
battlefield zone. His audience remained
adamantly opposed and unanimous that this scheme was also unacceptable, even if
the nuclear explosions took place in the United States. These reactions impressed upon Cohen the
depth of official feeling against the military use of nuclear explosives. “By now I realized that as long as a nuclear
explosive was used in anger, U.S. policy held the type of explosive and
geographical location of detonation to be absolutely irrelevant. The cardinal point was that it was the act
of detonating the explosive in anger that was a political taboo.”
Cohen’s fictitious weapons amounted
to an explicit––and ingenious––device for exploring the scope and content of
the taboo, which he did not personally share.
Indeed, the word “unthinkable” increasingly crept into discourse on
nuclear weapons. In a memo of September
12, 1967 to Walt Rostow, who had replaced McGeorge Bundy as national security
adviser, Robert Ginsburgh, Rostow’s deputy, listed seven military measures to
achieve a “more spectacular rate of progress” in the war. The last was “Create wasteland with low
yield nuclear weapons in southern part of North Vietnam––virtually
unthinkable.”
Return to Top
The War
Escalates
Both
the Joint Chiefs and General William Westmoreland, the American commander in
Vietnam, pressed for a more ambitious bombing program throughout 1966 and into
1967. They lobbied for major escalation of the war and more troops in 1966,
after the much-criticized Christmas 1965 bombing pause, and again in late May
1967. In a memo to McNamara on May 20,
1967, the Chiefs argued for increased air attacks on North Vietnam, and stated
their belief that invasions of North Vietnam, Laos, and Cambodia might become
necessary, involving the deployment of U.S. forces to Thailand, mobilization of
reserves, and, quite possibly, the use of nuclear weapons in southern
China. They recognized that these
actions could lead to confrontation with China and/or the Soviet Union in
Southeast Asia or elsewhere, but they considered such steps necessary to
shorten what they predicted would otherwise be five more years of war. McNamara later described that he was
“appalled” by the “cavalier” way in which the military recommended aggressive
policies, which in his view raised unacceptable risks of war with China
including possible U.S. use of nuclear weapons.
Return to Top
The 1966
Jason Report
The only known systematic study of
the role of tactical nuclear weapons in the war was conducted by four civilian
scientists consulting for the U.S. government as part of the JASONs---a group
of some forty young scientists who had met each summer since 1959 to consider
defense-related problems for the Pentagon. As the war escalated in the spring of 1966,
a high-ranking Pentagon official with access to President Johnson was heard by
a scientist to say, “It might be a good idea to toss in a nuke from time to
time, just to keep the other side guessing.” Freeman Dyson, one of the authors of the
report and a physicist at Princeton, recalled that this happened at a briefing
at the State Department or at an informal party, while Steven Weinberg, another
of the scientists, then on leave from Berkeley at Harvard, recalled a rumor
circulating that someone in the Pentagon or National Security Council was
pushing for the use of tactical nuclear weapons in Vietnam or Laos. These two----along with Robert Gomer and S.
Courtenay Wright, both at Chicago at the time---were so appalled by this statement
they decided something must be done.
Worried that nuclear weapons were
not “unthinkable” enough, the scientists obtained permission from the Defense
Department to carry out a systematic study of the likely consequences of using
tactical nuclear weapons in Vietnam.
They explicitly intended it to put a definitive end to any lingering
thoughts that such weapons might be useful in the war. Whereas Ball’s 1964 memo had emphasized
political consequences, this study focused on the military utility of nuclear
weapons in the conflict.
The group who took on this task was
not responding to specific nuclear war plans or threats, nor to a request from
the Pentagon. Dyson wrote later that he
had no evidence that the use of nuclear weapons was considered seriously in
prosecuting the Vietnam War. But, he
added, “We had no way to tell whether the speaker was joking or serious. Just in case he was serious, we decided to
do our study.”
“I, and I believe others as well,”
Weinberg wrote later, “felt that the use of nuclear weapons would make the war
even more destructive than it had already become; it would create a terrible
precedent for the use of nuclear weapons for something other than deterrence;
it wouldn’t help much with the war; and it would open up the possibility of
nuclear attacks on our own bases in Vietnam.
All this was an immediate reaction, not based on any careful
analysis. So we decided to do the
analysis and write a report.”
After “three man-months” of work, the authors produced a highly-classified
report titled “Tactical Nuclear Weapons in South-East Asia,” which presented
their analysis and conclusions in what Dyson later described as “a deliberate
hard-boiled military style.” The analysis sought to demonstrate “that even from
the narrowest military point of view, disregarding all political and ethical
considerations, the use of nuclear weapons would be a disastrous mistake.”
Recently
declassified, the 55-page report makes a strong case against the utility of
tactical nuclear weapons in Vietnam. The analysis focused on whether there would
be suitable targets in Vietnam for the tactical use of nuclear weapons, and on
the effects on enemy ground operations.
It defined tactical use “in the strict sense”—that is, on “military
targets, only within the theater of ground combat, and while avoiding civilian
casualties so far as practicable.” The
reason for this focus, the authors explained, “is that we wish to stay as much
as possible in the realm of technical military analysis and to avoid
involvement with political and moral judgments.”
The
analysis highlighted numerous military obstacles to the tactical use of nuclear
weapons: the difficulty of target
acquisition, and the fact that even when good targets existed, use of tactical
nuclear weapons would not substantially affect enemy operations. In some cases, there were more effective
alternatives.
The report
identified numerous targets against which, in principal, tactical nuclear
weapons would be useful. “Bridges,
airfields, and missile sites make good TNW [tactical nuclear weapons] targets.” Airfields were also “ideal targets for TNW
and are expensive targets for conventional bombing.” The introduction of tactical nuclear bombing would quickly render
the ten remaining operational airfields in North Vietnam inoperable. Other potential targets were large troop
concentrations, tunnel systems, and Viet Cong bases in South Vietnam. “TNW can be very effective if the position
of bases are known accurately, especially if attacks can be delivered without
warning.” Still, using tactical nuclear
weapons in South Vietnam would be
"helpful, but in no sense decisive. It would be equivalent to a major increase in the strength of
B-52 bombardments."
For
instance, it would take 3000 tactical nuclear weapons per year to interdict
supply routes like the Ho Chi Minh trail.
More problematically, U.S. forces might become vulnerable to a
Soviet-orchestrated counterattack; and that first use of tactical nuclear
weapons against guerillas might set a precedent that would lead to use of
similar weapons by guerillas against more vulnerable U.S. targets.
In
reality, the report concluded, few suitable targets or effective uses could be
found. “The use of TNW on troop targets
would be effective only in stopping the enemy from moving large masses of men
in concentrated formations. So long as
the enemy moves men in small groups and uses forest cover, he would offer few
suitable troop targets for TNW.” Using
“bomblet-canister ordnance” would be more cost-effective than using nuclear
weapons on troops in the open. Viet Cong base areas in South Vietnam could
be effectively destroyed with tactical nuclear strikes, “but this would require
large numbers of weapons and an accurate location of targets by ground
patrols.” Tactical nuclear weapons could also block
roads and trails in forested areas by blowing down trees, but fallen trees
could be relatively easily cut through and cleared.
Finally,
using fallout from groundburst weapons to make trails impassable would require
repeated use of nuclear weapons and “would not by itself provide a long-lasting
barrier to the movement of men and supplies, without endangering civilian
populations at up to a distance of 200 miles.” In conducting their analysis, the authors
drew in part on findings from RAND and Research Analysis Corporation nuclear
war-gaming studies from the late 1950s and early 1960s, as well as the 1965
OREGON TRAIL studies, which revealed the difficulties of timely troop target
acquisition.
The second half of the
report considered the vulnerability of U.S. forces to attack by insurgents
armed with tactical nuclear weapons supplied by the Soviet Union or China. U.S. bases, harbors and staging areas in South
Vietnam were vulnerable to Soviet bombers and infiltration by guerillas, and
would “offer attractive targets for [the retaliatory use of] TNW.” In fact, they were far more vulnerable to
the effective use of nuclear weapons than were the smaller, relatively mobile,
and difficult-to-find enemy encampments.
In
addition, the authors emphasized the “tremendous long-range importance” of
avoiding “setting a precedent for the use of TNW by guerilla forces.” U.S. forces, they wrote, would always be
much more vulnerable than insurgents to nuclear attack. The dangers posed by increased guerilla
activity around the world in the future “will certainly become more acute if
the U.S. leads the way by initiation of tactical nuclear war in Southeast
Asia.”
The report came to a
strong conclusion: “the overall result
of our study is to confirm the generally held opinion that the use of TNW in
Southeast Asia would offer the U.S. no decisive military advantage if the use
remained unilateral, and it would have strongly adverse military effects if the
enemy were able to use TNW in reply.”
Although
the study stated at the outset that it was intended be a purely technical
analysis, in fact it included strong judgments about the political costs and
consequences of using nuclear weapons.
The last section, “Political Consequences,” listed possible scenarios in
which the response to a U.S. use of tactical nuclear weapons was escalation,
although it did not estimate the relative probabilities of these
scenarios. “The ultimate outcome is
impossible to predict,” the authors noted.
“We merely point out that general war could result, even from the least
provocative use of NW that either side can devise.”
Most
significantly, they concluded that even if massive retaliation did not result,
U.S. first use of tactical nuclear weapons in Vietnam would have many serious
long-range consequences:
“The most
important of these is probably the crossing of the nuclear threshold. As Herman Kahn points out, abstention from
the use of any NW is universally recognized as a political and psychological
threshold, however rational or irrational the distinction between “nuclear” and
“nonnuclear” may be. Crossing it may
greatly weaken the barriers to proliferation and general use of nuclear
weapons. This would be to the ultimate
disadvantage of the U.S., even if it did not increase the probability of
strategic war.”
Whether or not the Vietnamese National Liberation
Front or its external allies countered with use of nuclear weapons of their
own, the authors argued, the effect of a U.S. nuclear first use on world
opinion in general and on U.S. allies in particular would be “extremely
unfavorable. With the exception of
Thailand and Laos, the reaction would almost certainly be condemned even in
Asia and might result in the abrogation of treaty obligations by Japan.” The effect on public opinion in the United
States “would be extremely divisive, no matter how much preparation preceded
it.” “In sum,” they concluded, “the political effects of U.S. first use of TNW
in Vietnam would be uniformly bad and could be catastrophic.”
From
a purely military perspective, therefore, even if the target acquisition
problem could be solved (and that was not evident), for tactical nuclear
weapons to be effective they would have to be used in such large quantities
(and with such great frequency) that political costs would outweigh military
benefits. When the risk of retaliation was added in, along with the risk
of the weapons spreading to guerilla forces around the world, it amounted to a
strong argument against the use of tactical nuclear weapons in the war.
The report is curious in some respects. It focuses on scenarios that were already at
the time widely regarded as unlikely, such as the use of nuclear weapons
against insurgents. The Soviet supply
of tactical nuclear weapons (the report mentioned atomic mortars or recoilless
rifles) to North Vietnamese forces was also an unlikely scenario, given how
tightly the Soviet Union controlled its nuclear weapons. Further, the report pays no attention to
what was actually in the U.S. nuclear war plans for Southeast Asia in the
mid-1960s. These puzzling features can
perhaps be explained by the circumstances which motivated the scientists to
undertake the study (and the Defense Department to agree to it), discussed
further below.
A final interesting aspect of the
study is the way the four scientists, who personally found nuclear weapons
morally objectionable, took pains to couch their argument against use of
nuclear weapons in purely military terms, believing that this would enhance its
reception with military planners and decisionmakers in the Pentagon and CIA,
its most likely audience. As Weinberg
later described, using nuclear weapons in Vietnam seemed like “a terrible idea
for a host of ethical and moral, but also possibly political reasons.” He explained further that “Although my
objections were ethical and political, I also thought it was likely one could
make a good case from a purely hard-boiled military view, but I didn’t know.”
He thus participated in the study with some expectation that this would be the
case. The authors themselves viewed the report as
offering a powerful critique of the utility of nuclear weapons in the war.
“That paper gives all the reasons why you wouldn’t use nuclear weapons in
Vietnam,” observed one of its authors in a later interview.
Return to Top
Did the
Study Have Any Effect?
The fate of this report, and its role, if any, in
influencing the administration’s thinking on the role of nuclear weapons in the
war, remains vague. The authors handed
it to their sponsors in the Defense Department, never to hear of it again. However, Seymour Deitchman, at the time at
the Institute for Defense Analyses (IDA), a federally funded research center
under contract to the Defense Department, and acknowledged in the report, wrote
later that the report went to McNamara’s office. IDA provided administrative and technical support for the JASON
group. Deitchman recalled briefings on
the JASON studies of that summer to three audiences: the JASONs themselves, John McNaughton—then Assistant Secretary
of Defense for International Security Affairs, who managed the JASON
relationship with McNamara, and McNamara himself.
Deitchman recalled clearly the
nuclear weapons study briefing to the JASONs.
“I remember being struck by the main conclusion, that if we started down
that route [using nuclear weapons] we risked being hurt much more than the
North Vietnamese and the Viet Cong...”
McNamara received briefings on the JASON studies every year, and,
according to Deitchman, was likely briefed in late August or early September
1966. This probably included a briefing
on the nuclear weapons study, although Deitchman did not remember for sure. According to Deitchman, after the briefings,
the report was never circulated.
Since the Defense Department had to
sign off on the topics for the JASON studies (which were chosen by the JASONs
themselves), why would it agree to a study on tactical nuclear weapons in
Vietnam? Here we have only faint but
intriguing outlines. Deitchman recalled
recurring talk around the Pentagon that spring and summer about using tactical
nuclear weapons to block passes between North Vietnam and Laos, especially the
Mu Gia Pass, a key part of the supply route heading south. The pass was heavily and unsuccessfully
bombing by B-52s starting in July 1966, with heavy losses for the United
States. Thus when the JASONs proposed
the nuclear weapons study topic, McNaughton and McNamara might have found it a
useful device for showing what a bad
idea using nuclear weapons would be.
It thus remains unclear what effect
the report had. It is likely that it
had little or no influence on McNamara himself—because he was already adamantly
opposed to use of nuclear weapons. By
that point in time (1967), he was also increasingly skeptical that the war
could be won by deploying more troops to South Vietnam and intensifying the
bombing of North Vietnam (he offered his resignation to Johnson in November of
that year, largely over disillusionment with the war). In a later interview, McNamara did not
remember the study or the briefing, but conceded that the briefing could have
happened. He said that he himself would
have had no need for such a study, since he and his assistant McNaughton were
already totally opposed to nuclear weapons, but that did not mean it wasn’t
useful.
It might have, for example, helped
him put an end to loose talk about nuclear options. When Deitchman returned to the Pentagon in the fall of 1966, he
heard no further talk of using nuclear weapons in Vietnam. “Although I don’t know,” he recalled, “I
think it is reasonable to conclude from that that, if consideration had been
given to the idea before the study, Mr. McNamara simply dismissed it as
something not to think about seriously, and therefore the talk simply went
away.”
Return to Top
Khe
Sanh
The one attempt by the Johnson administration to look more closely at
the military utility of nuclear weapons––to relieve the siege of the Marine
garrison at Khe Sanh in early 1968––aborted quickly in a public relations
nightmare. This was perhaps the moment
of gravest risk of the kind anticipated by the JASONs. New evidence suggests that top
administration officials discussed the topic at several meetings throughout the
tense key days of late January and early February 1968, albeit with a tone of
the greatest reluctance. Johnson made clear he had no wish to face a
decision on use of nuclear weapons and repeatedly sought assurance from
military leaders that they had adequate conventional forces to defend Khe
Sanh.
In a memo to General Wheeler on
January 31, 1968, Robert Ginsburgh, Walt Rostow’s deputy on the National
Security Council and its liaison to the JCS, noted that if a desperate
situation developed at Khe Sanh, where 6000 Marines were besieged by
15,000-20,000 North Vietnamese troops, “the issue of TAC NUCS will be
raised.” Ginsburgh asked Wheeler
whether contingency target analysis would be in order. Handwritten on the memo were notations that
plans should be “very very very closely held.” Ginsburgh and Rostow had apparently already
been discussing the issue for a week or so.
The next day Wheeler solicited the
views of General Westmoreland and Admiral Ulysses Sharp, American commanders in
Vietnam, on whether nuclear weapons should be used if the situation became
desperate. Noting the perceived
parallels between Khe Sanh and Dien Bien Phu, he asked whether there were
suitable targets for nuclear strikes, whether some contingency planning might
be in order, and “what you consider to be some of the more significant pros and
cons.” He cautioned them to “hold this
subject very closely.” Westmoreland and Sharp had apparently
already been discussing the need for some planning on the issue, and had
already instituted it “under the strictest need to know basis,” Sharp wrote
back the next day. All three military leaders thought the use
of nuclear weapons an unlikely eventuality but felt military prudence alone
required some such planning.
As requested, Westmoreland began to
convene a secret study group to analyze nuclear options. But almost immediately Washington quashed
it, fearing––too late––that it would leak to the press. Johnson’s political advisers reversed
course, moving rapidly to forestall any request for a nuclear option from the
JSC by making sure Westmoreland had all the conventional forces he needed to
defend Khe Sanh. Rostow suggested in a
memo to the president on February 2 that Westmoreland be offered an extra reserve
division, explaining his “desire to avoid a situation of battlefield crisis in
which Westy and the JCS would ask you to release tactical nuclear
weapons.” He also urged that General
Wheeler be informed that it was his duty to minimize the likelihood that the
Chiefs would raise the nuclear issue.
In a memo the next day General
Wheeler sought to reassure the president, writing that “the use of nuclear
weapons should not be required in the present situation.” But he did not rule them out. “Should the situation in the DMZ area change
dramatically, we should be prepared to introduce weapons of greater
effectiveness against massed forces.
Under such circumstances I visualize that either tactical nuclear
weapons or chemical agents would be active candidates for employment.” In a memo to Johnson the same day,
apparently spurred by suggestions in the press and other parts of the
government that high-level considerations of nuclear weapons were under way,
Rostow apologized for his blunder in raising the issue with General Wheeler and
the commanders, which inadvertently created the impression that the government
was thinking about using nuclear weapons.
He explained that it was never his intent that any “formal staff work”
be done on the nuclear issue, adding that “the fault, therefore, is mine.”
In other words, not only should
nuclear weapons not be used, nuclear options should not even be studied. No analysis should be permitted, nor even
the appearance of it. The taboo
qualities emerge sharply here––something that is not done, not said, not
analyzed, not thought about. Not even
Walt Rostow should be permitted to analyze the issue. Johnson was later furious about the “irresponsibility with
respect to our planning to use nuclear weapons.”
Westmoreland, a consistent advocate
of greater force in Vietnam, wrote in his memoirs that he thought consideration
of tactical nuclear options at Khe Sanh a prudent idea. The region around Khe Sanh was virtually
uninhabited so civilian casualties would be minimal. He saw analogies to the use of atomic bombs in WWII to send a
message to Japan, as well as to the role of U.S. nuclear threats to North Korea
which many thought had ended the Korean war.
He wrote that “use of a few small tactical nuclear weapons in
Vietnam––or even the threat of them––might have quickly brought the war there
to an end.” If Washington officials
were so intent on “sending a message” to Hanoi, surely small tactical nuclear
weapons would do this effectively.
Westmoreland felt at the time and even more strongly later that failure
to consider the nuclear alternative was a “mistake.”
Despite the administration’s
efforts, rumors that it was contemplating the use of tactical nuclear weapons
in Vietnam swirled nonetheless, and the resulting popular outcry illustrated
the extreme sensitivity of the issue.
When Senator Eugene McCarthy, campaigning for president, aired the
matter publicly a few days later, the White House and Pentagon vehemently
denied that nuclear weapons were under consideration. General Wheeler told a Senate subcommittee
that he did not think nuclear weapons were needed for Khe Sanh’s defense, but
if it developed that they were, the JCS would recommend to President Johnson
that they be used. On February 9, testifying before the Senate
Foreign Relations Committee, Rusk denied the existence of any plans for use, or
of stockpiles, of nuclear weapons in Vietnam, but failed to rule it out
entirely. Senator Fulbright, chairman
of Committee, along with Senators Clark and Aiken, denounced the possibility of
use of nuclear weapons. The Congressional inquiry was prompted in
part by speculations about the reasons for sending four nuclear scientists to
Vietnam. The scientists were in fact being sent to study the “McNamara
line”––an electronic barrier to prevent North Vietnamese infiltration across
the demilitarized zone separating the two Vietnams. Their trip had nothing to do with nuclear
weapons. British Prime Minister Harold
Wilson, on a visit to Washington during this debate, said bluntly during an
interview on CBS’s “Face the Nation” that it would be “sheer lunacy” for the
United States to use tactical nuclear weapons.
It would not only be “disastrous” to America’s position, he said, but it
would also “run a very, very great risk of escalation for the world.”
However, a few public figures called
for use of nuclear weapons.
Representative Wayne Hays a member of the House Foreign Affairs
Committee, disagreed with the critics, saying, “Rather than suffer a disastrous
defeat and the annihilation of a considerable number of our forces, I think we
would just be foolish and completely stupid if we got in that (Khe Sanh)
position and did not use them.” Congressman Charles Bennett called for
“whatever forces are needed” to win the war including “even the threat or use
of atomic weapons and the invasion of North Vietnam” if necessary.
In a press statement on February 9 and again during a press
conference a week later, President Johnson denied strongly that he had received
any request from his military or political advisers to use nuclear weapons in
Vietnam. He emphasized that any
decision to use nuclear weapons rested with the President. In his seven years in the Executive Branch,
he said, “no recommendation has been made to me” about deployment of nuclear
weapons. “Beyond that, I think that we
ought to put an end to the discussion.” Press Secretary George Christian made clear
that the Johnson administration was upset that the nuclear weapons question had
been raised at all. “Irresponsible
discussion and speculation are a disservice to the country...” he stated.
Johnson’s categorical denial was
probably somewhat overstated, since the nuclear weapons issue had been
discussed at the regular Tuesday luncheon at the White House among the
secretaries of defense and state, the president and General Wheeler. It was true that the president had not
received any requests for use of nuclear weapons. However, he had not received definite assurances from the JCS
that they would never make such a request; the military chiefs were not able to
give Johnson the categorical assurance that Khe Sanh could be held without
nuclear weapons, under bad weather conditions that hindered conventional air
support.
After prominent scientists George
Killian, George Kistiakowsky and I.I. Rabi expressed concern in a telegram to
Eisenhower about the possible use of nuclear weapons in Vietnam, McNamara
called each of them personally to assure them that there was no consideration
of use of nuclear weapons. They had
been inspired to write in part by a newspaper report in which Eisenhower was
reported to have left the door open for use of nuclear weapons in South
Vietnam. Although Eisenhower was no longer president,
his record as a distinguished general gave his views on military issues some
weight.
Overall, during the Khe Sanh crisis,
political leaders displayed much greater concern, and spent much more time
dealing with, the public relations dimension of nuclear weapons than their
actual utility at Khe Sanh. As a Washington Post article put it,
“Pentagon weapons experts contended the technical problems were almost as large as the political
problems in using nuclear weapons.” In other words, political constraints posed
an even greater obstacle to the freedom to use nuclear weapons than their
technical difficulties––in this case, primarily radioactive fallout. On March 9, the Washington Post editorialized
that use of nuclear weapons in Vietnam would be a “disaster.” When Johnson administration officials met
with the “Wise Men”––a group of former high officials consulting on U.S.
military options in Vietnam––a month later, on March 25, to make decisions on
the failing war effort in the wake of the Tet offensive, the nuclear “lesson”
of Khe Sanh was likely reflected.
Rejecting a new troop request of 200,000, they also concluded, with no
evident discussion, that “use of atomic weapons is unthinkable.”
The administration did ensure that
Westmoreland had sufficient conventional forces to defend Khe Sanh. The battle that took place there was, in
Westmoreland’s words, “an awesome display of firepower; given the bomb-delivery
capacity of the B-52s, one of the heaviest and most concentrated in the history
of warfare.” B-52s eventually dropped more than 100,000
tons of explosives on a five-square-mile battlefield. At Westmoreland’s request, Johnson did
permit the use at Khe Sanh of so-called controlled fragmentation munitions
(COFRAM), shells and grenades, some containing submunitions, that exploded with
very lethal effects. Information on the
existence and use of this weapon was guarded as closely as possible.
Return to Top
Public Opinion
Even in the face of the growing
number of American casualties in Vietnam, public opinion remained opposed to
use of nuclear weapons in the war. U.S.
public opinion had consistently been against the first use of nuclear weapons
since the mid-1950s. The moderate
amount of polling on the topic during the Vietnam War showed that, in terms of
public opinion, the taboo against first use held during the war, even while
American casualties mounted.
In the first stages of the war
(1964-66), there was only limited support for using nuclear weapons––about 15%
approved taking such a step. As the war
continued, support for using nuclear weapons increased to 24 percent and then
to 42 percent. But on a question asked both before and
after the winter 1968 Tet offensive about the use of “atomic ground weapons,” a
Harris poll found the answer the same in both cases: about 25 percent in favor, 55 percent opposed. When the question was worded more
aggressively––whether respondents would agree or disagree with the view that
“we should go all-out to win a military victory in Vietnam, using atomic bombs
and weapons,” some 26 percent approved and, higher than on the Harris “ground
weapon” question, about 65 percent
disapproved.
Thus attitudes in support of using
nuclear weapons in Vietnam never reached a plurality or majority. Not only did the public largely reject using
nuclear weapons, but toward the end of the war a survey of elite leaders
indicated they rejected it also.
Further, as Thomas Graham has reported, a more diverse base of survey
questions showed that the taboo applied not only to Vietnam, but to other
proposed uses of nuclear weapons as well, suggesting the more general nature of
the sentiment. This pattern of public attitudes (low
support at first, then higher, but only under certain limited conditions) fits
the same general pattern found in the Korean War, although the magnitudes
differ. The American public was less
willing to recommend the use of atomic weapons in Vietnam than in Korea.
At a retrospective conference on the
Vietnam War in 1997, McNamara denied
forcefully that world public opinion constrained U.S. use of nuclear weapons in
Vietnam. He insisted instead that “it
was because it was neither militarily desirable nor morally acceptable.... It
had nothing whatever to do with what the world might have thought about it.” He
continued, “...Presidents Kennedy and Johnson made clear and concrete,
unqualified decisions not to use nuclear weapons––particularly because it was
considered morally unacceptable. That
was also my recommendation to them. I
was with each of them, on separate occasions, when they made these
decisions. The use of nuclear weapons
in Vietnam was never considered viable.”
Given the significant role that
negative public opinion played in shaping American decisionmaking on the war
more generally, McNamara’s strong claim might seem implausible. However, his views on nuclear weapons were
shaped well before U.S. intervention in Vietnam—through his experiences of
crises over Berlin, Laos and Cuba. His
statement underscores the degree to
which he and others believed that using nuclear weapons was simply “wrong;”
i.e. that it was not a matter of appeasing other’s views, rather “WE thought it
was wrong.”
Return to Top
Nixon and Kissinger
In stark contrast, the taboo
operated primarily as an instrumental, rather than substantive, constraint on
the top officials of the Nixon administration, who exhibited no such personal
reluctance to thinking about nuclear options.
President Nixon, the archetypal anti-communist hawk, dreamed of ending
the Vietnam war with a “knockout blow.”
He believed approvingly that U.S. nuclear threats had ended the Korean
war, and expected to utilize the same principle of the threat of excessive
use of force to bring victory in Vietnam.
Describing his “madman theory” to longtime aide H.R. Haldeman in fall
1968, he would convince North Vietnamese leaders that he was obsessed with
winning the war and willing to unleash the most ruthless violence against their
country if they did not end it, implying a nuclear threat.
Nixon was a strong advocate of U.S.
nuclear superiority and, like Eisenhower, whom he had served as vice president,
a believer in the efficacy of nuclear threats.
Although he believed a nuclear war with the Soviet Union would be a
disaster, he does not appear to have viewed nuclear weapons themselves with any
particular moral compunctions. In every
Cold War crisis, Nixon had always urged escalation and greater use of
force. As Vice President in 1954 under
Eisenhower, he had supported the deployment of U.S. troops to replace French
losses in Vietnam and the following year had advocated that the United States
use atomic weapons to halt Chinese moves into Vietnam. In 1964 he had urged retaliatory strikes
against Laos and North Vietnam. The
following year he opposed the Johnson administration’s efforts to start
negotiations on the ground that the North Vietnamese would regard it as
evidence of weakness. He had opposed
constant calls for negotiation since those would only encourage Hanoi. During the 1968 presidential campaign, he
attacked the Johnson administration for its policy of gradualism in the use of
force. He often told aides in the early days of his
administration, “I don’t intend to be the first president to lose a war.”
Nixon, who prided himself on being
tough, stated in an interview with Time
magazine in 1985 that he had considered the use of nuclear weapons four times
during his administration, one of which was to end the Vietnam War. He told Time that he had rejected the
bombing of dikes, “which would have drowned 1 million people, for the same
reason that I rejected the nuclear option.
Because the targets presented were not military targets.”
However, Henry Kissinger, Nixon’s
national security adviser, repudiated Nixon’s claim publicly. Kissinger reported in an interview that
"I can safely say that there was never a concrete occasion or crisis in
which the use of nuclear weapons was considered by the government." He added, “None of these crises reached a
point where there was any planning to use nuclear weapons. There was never any decision––even
contingent decision––to use nuclear weapons if such a contingency should
arise. And there was never any
discussion of how far we would be prepared to go in these contingencies.”
These statements, and the record on Nixon’s and Kissinger’s
attitudes toward the use of nuclear weapons more generally, are difficult to
interpret. Because of Nixon’s penchant
for hyperbole and inflated rhetoric, and because key memoir accounts of this
period are unusually ideological and selective, the evidence often appears
contradictory. Some of the Vietnam
files of Nixon’s and Kissinger’s papers have recently been opened to the
public, but a full account must await a future telling. According to Stephen Ambrose, a leading
Nixon biographer, in Nixon's considerations of how to end the war, use of atomic
weapons "on the model of Japan in WWII" was "out of the
question." However, it does not seem to have been
entirely out of the question, and especially not for Kissinger, whose denial
appears overstated with respect to the case of Vietnam.
During the review process of Vietnam
even before his inauguration, Nixon says he considered and––with apparent
regret––rejected either bombing dikes or using nuclear weapons, saying he
“could not allow my heart to rule my head”––his heart wanting the knockout
blow, his head constrained by the public outrage he knew it would provoke. Had he chosen either of these courses of
action, he acknowledged, “the resulting domestic and international uproar would
have damaged our foreign policy on all fronts.” He also noted it would have hampered
improved relations with the Soviet Union and China. His reasoning was instrumental, and he never ruled out use of
nuclear weapons in general.
Earlier, during both the 1964 and
1968 presidential campaigns, Nixon had come out against use of nuclear weapons
in Vietnam. In August 1964, Nixon had
written a Readers’ Digest article,
“Needed in Vietnam: The Will to Win,”
in which he had put only one limit on what should be done in Vietnam: “I am firmly opposed to the use of nuclear
devices of any sort, not only because of the disastrous effect this would have
on world opinion, but because it is wholly unnecessary.” In late January 1965 he advocated U.S. naval
and air bombardment of North Vietnam, while saying that ground forces would not
be necessary and reiterating that nuclear weapons should not be considered. Four years later, running again for
president, Nixon got a great break when, in October 1968, presidential
candidate George Wallace announced that he had chosen General Curtis LeMay,
former head of the strategic nuclear bombing command, as his running mate. LeMay, in his first press conference, said
that he would use nuclear weapons immediately in Vietnam. Nixon said he "disagreed
completely" and accused Wallace’s American Independent Party of
irresponsible and excessively hawkish attitudes on foreign affairs. Wallace went down to defeat, with 13.5
percent of the popular vote. Nixon’s
public opposition during his campaigns to use of nuclear weapons in Vietnam
appeared to be dictated largely by the instrumental needs of the campaign,
since, according to his own account, once he gained the presidency, the nuclear
option was one of the first things he thought about.
Nixon’s interest in exploring
nuclear options as president was matched, and perhaps even exceeded, by that of
his National Security Adviser Henry Kissinger.
Kissinger, in his former life as an academic, had written a bestselling
book, Nuclear Weapons and Foreign Policy,
which advocated use of tactical nuclear weapons in limited wars. Increasingly critical of nuclear strategies
based on massive retaliation, he argued that strategies of limited war and
limited nuclear war would be more useful for both warfighting and diplomacy. Since the publication of the book in 1957,
Kissinger had drawn back from aspects of that policy, but he continued be a
strong advocate of the development of limited nuclear options. In a March 1976 interview in U.S. News and World Report, Kissinger
admitted publicly that, although nonnuclear means of responding to aggression
was preferable, he would not exclude the use of nuclear weapons in certain
limited situations.
At his instigation, one of the first
goals of the Nixon White House was to revise U.S. nuclear strategy to provide
for more limited nuclear options. The
day after Nixon’s inauguration on January 20, 1969, Nixon and Kissinger had
ordered NSSM-3 (National Security Study Memorandum), a study of the
conventional and nuclear balance of forces.
Completed in May, it emphasized the need for limited nuclear options, a
view with which Kissinger was highly sympathetic. The first week in office, the JCS had presented to Nixon and
Kissinger a deeply pessimistic briefing on the Soviet nuclear arms build-up. The Soviet Union was approaching parity with
the United States in nuclear forces and might even achieve superiority. For Kissinger, the impending loss of U.S.
strategic superiority required a rethinking of U.S. nuclear strategy. The
threat of nuclear use needed to be more plausible than simply threatening
all-out war.
NSSM-3 led to a follow-on study in
June 1969 requesting the NSC and the Pentagon to examine limited nuclear
targeting options. Kissinger wanted the NSC staff to develop a
strategy in which the nuclear options actually seemed usable. But by the spring of 1970, the
administration had to put the strategic review on the back burner. Despite pressure from Kissinger, the NSC
staff moved slowly on the study, in part because the development of limited
nuclear options seemed a low priority in the face of other more pressing
matters such as the Vietnam War and the upcoming SALT negotiations. But, increasingly, the White House
encountered opposition from State Department officials who worried that the
ready availability of plausible nuclear options would make recourse to the use
of nuclear weapons much more likely.
They also feared it would generate demands from the military for more
weapons systems, and arms control supporters worried that the development of
limited options would torpedo the SALT negotiations.
Return to Top
Vietnam
Contingency Planning
During this same period, planning
began on more aggressive options for Vietnam.
On January 27, 1969, Nixon, Kissinger, General Wheeler, and Secretary of
Defense Melvin Laird met to discuss military options “which might jar the North
Vietnamese into being more forthcoming at the Paris talks.” On February 21, Laird forwarded to Kissinger
a very preliminary JSC report on the matter.
The top secret report identified five fairly aggressive scenarios, the
last one involving what it referred to as “technical escalation,”---use of
atomic, biological or lethal chemical weapons.
In evaluating this option, the report noted that use of such weapons in
Vietnam “would excite very strong public and Congressional reaction,” adding
that “the predictable reaction worldwide [to this scenario], particularly in
Japan and Okinawa....militate against its employment.”
Neither Laird, Kissinger, nor
Kissinger’s military assistant Alexander Haig were favorably disposed toward
the proposals. In transmitting the
report to Kissinger, Haig commented that the plans were “more extensive than
the type you and the President visualized as acceptable signals of US intent to
escalate military options in Vietnam.” Kissinger
found the plans “well conceived” but that the “realities” of the current
domestic and international environment did not lend themselves to accepting at
this time the risks they laid out. He
suggested more “subtle” actions which might have “reduced risks of news media
recognition or domestic turbulence,” such as increased military communications
and increased aerial reconnaissance, activities which might create the
impression of a U.S. force build-up.
Return to Top
Operation Duck Hook
Shortly, however, Kissinger chose to look into the less subtle
options. During the same period that
the NSC was being tasked to study limited nuclear options, Kissinger was
investigating nuclear contingencies with respect to Vietnam. The key case is operation Duck Hook, a plan
for a massive use of force against North Vietnam developed in the spring and
summer of 1969. Developed by Kissinger and a few associates,
it called for massive bombing of Hanoi, Haiphong, and other key areas in North
Vietnam; the mining of harbors and rivers; the bombing of the Red River dike
system; a ground invasion of North Vietnam; the blockading of Sihanoukville,
the destruction––possibly with nuclear weapons––of the main north-south passes
along the Ho Chi Minh Trail; and the bombing of North Vietnam’s main railroad
links with China. A separate, even more
secret study dealt with the implications of using tactical nuclear weapons on
the rail lines, the main funnel for supplies from the Soviet Union and China. According to Haldeman, Nixon’s chief of
staff and confidante, Kissinger had lobbied for nuclear options in the spring
and fall of 1969.
In late August, Nixon reviewed “K’s
contingency plan for Vietnam” but did not make a decision one way or
another. In late August and into
September, Kissinger feared that Nixon’s mental resolve for a resolute stance
on the war was wavering, and he took steps to urge him to approve what was
being referred to as the November Option––a “savage, decisive blow” against
North Vietnam to end the war. On September
9, Kissinger met with General Wheeler to “discuss military planning for the
Duck Hook operation...and to convey to him the president’s personal mandate
that planning be held in strictly military channels,” which would
thereby preclude discussing the plan even with the secretary of defense.
In late August or early September,
Kissinger assembled a select group of his staff to undertake a top-secret study
“to explore the military side of the coin”––that is, the existing Duck Hook
studies. He described it to them as a “very, very
sensitive matter.” In White House Years, Kissinger wrote that
he told the group that what was needed was a “military plan designed for
maximum impact on the enemy’s military capability” in order to “force a rapid
conclusion to the war.” These options might include the use of a
tactical nuclear weapon in a single, carefully controlled situation. A top secret “Concept of Operations”
document of mid-September stated U.S. resolve “to apply whatever force
necessary” to achieve basic U.S. objectives in Southeast Asia. International and domestic pressures, and
the possibility of Soviet or Chinese reaction would be important factors “but
will not necessarily rule out bold or imaginative actions....”
The document did note that bombing the dikes would raise “particular problems”
in the United States.
Kissinger told the group, “I refuse
to believe that a little fourth-rate power like North Vietnam doesn’t have a
breaking point. The Johnson
administration could never come to grips with this problem. We intend to come to grips.” When one staff member asked about the
possible use of nuclear weapons, Kissinger replied that it was “the policy of
this administration not to use nuclear weapons.” But he did not exclude the use of “a nuclear device” to
block a key railroad pass to China if that should prove the only way of doing
it. One participant recalled later that
“I guess we were all in a sort of a mild state of shock.” The emphasis of the scenarios was on
delivering savage air blows, to be repeated at intervals. The study was conducted only on the basis of
military effectiveness. Few moral or
political considerations entered the picture.
According to an NSC aide, “The whole exercise struck me as being very
cool and amoral, not judging it in terms of the loss of life or in terms of the
escalation of the war, but simply in terms of effectiveness.”
It remains unclear whether the
special group ever actually considered in its study the possible use of a
nuclear device as part of its proposed blockade of North Vietnam. Tad Szulc reports that it did not, and that
Kissinger is not known to have alluded to it again. Kissinger aide Roger Morris said that he had
been shown nuclear targeting plans, while other aides later told interviewers
that they did not recall encountering any evidence that Nixon and Kissinger
considered using a nuclear device in the Duck Hook operation. Haldeman apparently opposed use of nuclear
weapons in Vietnam primarily because it might hurt Nixon’s reelection chances
in 1972.
During September and October, Nixon
continued his threats of dramatic escalation of the war. To bolster them, he ordered a secret
worldwide nuclear alert, one of the largest secret military operations in U.S.
history. It began October 13 and lasted
a month. However, as massive public protests against
the war scheduled for October 15 and November 13-15 in the United States
loomed, Nixon cancelled Duck Hook. In
his memoirs, he suggests that the world-wide furor over escalation of the war
undermined his plans.
An NSC staffer remembered it differently, recalling that the attack plans were
narrowly defeated mainly because of “Nixon’s uncertainty about military
efficiency, not because of any larger doubts rooted in concern for domestic or
foreign consequences.” Kissinger had backed away from the plan,
persuaded in part by lengthy memos from NSC aides opposing the escalation
plans, in particular a scathing and detailed critique of the military operation
by Lawrence Lynn, a former Pentagon official then on the NSC staff, arguing
that the blockade would not work.
Suppose Nixon been able to secretly use tactical nuclear weapons in
Vietnam along the lines of the secret bombing of Cambodia? There is little reason to think he would not
have done so. On May 11, 1969, Nixon,
Kissinger and other aides were on board a top secret Airborne Command post jet
returning to Washington from Key Biscayne.
Nixon read a report on nuclear operations plans which had been completed
a few days earlier. One of the study’s
findings was that the SIOP contained no flexible limited options in its massive
strike scenarios. Nixon had scribbled a
few notes on yellow pad, now declassified:
“These plans are a disgrace.
They really have no options outside these in last, because if you use
the force separately the SIOP becomes impossible. If in doubt we bomb Cambodia.” Does this suggest they were thinking about
nuclear contingency plans for North Vietnam?
It is unclear.
As it was, Nixon kept the Duck Hook
planning secret from even his secretaries of state and defense, William Rogers
and Melvin Laird. When they found out
about it––only when Nixon himself leaked the plan––they urged against it,
emphasizing the mounting public opposition to escalating the war. Two scientists who were consulted on the
Duck Hook nuclear targeting plans opposed the nuclear course of action, for
both military and moral reasons.
With the notable exception of the maverick Samuel Cohen, most
scientists and civilian defense analysts involved in policy advising opposed
use of nuclear weapons in Vietnam, for both military and moral reasons. Daniel Ellsberg, at the time a defense
analyst at RAND, directed a comprehensive study of U.S. military options in
Vietnam requested by Kissinger in late 1968.
Ellsberg adamantly refused to consider tactical nuclear options in the
study. “I wouldn’t be party to a paper
that suggested in any way that nuclear weapons deserved any consideration in
Vietnam,” he recalled later. The two scientists who had been asked to
review the Duck Hook nuclear target folders in 1969 were distressed at the
nuclear option, one of them worrying that use of nuclear weapons might bring in
the Chinese. They urged Paul Doty, a
leading Harvard biochemist and a friend of Kissinger’s, to discourage the
planning, and conveyed the same views to Haldeman, an old acquaintance of one
of the scientists. Even physicist Edward Teller, one of the
nation’s most hawkish scientists, and a longstanding proponent of nuclear arms,
opposed using nuclear weapons in Vietnam on the grounds that they would not be
useful against guerillas. Branding
those who advocated use as “idiots,” he proclaimed that, “Only a few
idiots––and they were really idiots––suggested using nuclear weapons in Vietnam.” Kissinger, however, did not have much use
for scientists, especially because scientists on the President’s Science
Advisory Committee did not give him the advice he wanted on ABMs. They appear to have had little impact on his
thinking about nuclear weapons.
Return to Top
Spring
1972: In Final Pursuit of the Knock-Out
Blow
In
the spring of 1972, Nixon was considering escalation options in North Vietnam
that would go “far beyond” an all-out bombing attack. According to recently released White House tapes, on April 25, a
few weeks before he ordered a major escalation of the war, Kissinger presented
him with a series of escalation options, including attacking North Vietnamese
power plants and docks. Haldeman and
press secretary Ron Ziegler were also present.
Nixon said, “I still think we ought to take the dikes out now. Will that drown people?” Kissinger responded, “About 200,000 people.” Nixon stated, “No, no, no...I’d rather use
the nuclear bomb. Have you got that,
Henry?” Kissinger replied, “That, I
think, would just be too much.” Nixon
responded, “The nuclear bomb, does that bother you?... I just want you to think big, Henry, for
Christssake.”
According to Haldeman’s diary,
Nixon, Kissinger and Haig again discussed the possible use of nuclear weapons a
week later, on May 2, as peace negotiations became intractable. The topic arose during a meeting on the
presidential yacht Sequoia, shortly
after Kissinger’s return from the Paris negotiations, in the context of a
discussion of military options to end the war.
Nixon rejected the nuclear option, as well as an invasion of the North
and the bombing of Red River dikes. He
favored instead the blockading of North Vietnamese ports and the expansion of
bombing north of the 20th parallel, commenting that he wanted “that place
bombed to smithereens.”
On May 4, discussing his decision
with Kissinger, Haig and John Connally, Nixon thumped on his desk as he railed
“...South Vietnam may lose. But the
United States cannot lose...Whatever
happens to South Vietnam, we are going to cream North Vietnam.....For
once, we’ve got to use the maximum power of this country...against this shit-ass
little country....” The next day during a conversation
Nixon observed to Kissinger that civilian casualties are a result of all wars.
“The only place where you and I disagree…is with regard to the bombing. You’re so goddamned concerned about the
civilians and I don’t give a damn. I
don’t care.” Kissinger responded, “I’m
concerned about the civilians because I don’t want the world to be mobilized
against you as a butcher. We can do it
without killing civilians.”
Nixon’s suggestions to use nuclear
weapons against North Vietnam, or to implement other drastic measures that
would kill a lot of civilians, were clearly reflections of his frustration with
the war. They were not a live
option. It was clear by this point in
the war---as it had really been clear all along---that use of nuclear weapons
was not politically feasible, either domestically or internationally. Nixon clarified this himself in an NSC
meeting on May 8, when he called for a "cold-blooded analysis" of the
current situation in Vietnam. After a
discussion of mining options, Nixon explained, "Whatever we do we must
always avoid saying what we're not going to do, like nuclear weapons. I referred to them saying that I did not
consider them necessary. Obviously, we
are not going to use nuclear weapons but we should leave it hanging over
them. We should also leave the threat
of marines hanging over them....we shouldn't give reassurance to the enemy that
we are not going balls out."
Thus Nixon, who clearly harbored few
personal inhibitions about violating an array of important democratic norms
during his presidency when he thought could get away with it, was powerfully
constrained by the abhorrence and opposition of others. The restraint that he did display with
regard to use of nuclear weapons was primarily the result of public opinon
constraints. Haig, a hard-liner who had
served in Vietnam and later became secretary of state, and who had helped plan
Duck Hook, attributed the nonuse of nuclear weapons in Vietnam and other Cold
War conflicts to normative concerns----of others. He wrote in 1992, “On the American side, the moral argument
against the use of such weapons, or even the threat of their use, took on the
force of religious belief.” He argued against this moral perspective and
worried that such inhibitions would undermine deterrence. “Nevertheless,” he wrote, “....the mere
existence of our superior power often bailed us out of potential disaster even
though we were determined, in the depths of the national soul, never to use
it.” Because of such moral inhibitions, he felt
that no American president would resort to nuclear weapons except in the extreme
case of the defense of Europe.
Referring to something as a
religious belief suggests that it is held as a matter of faith and fervor, and
is unsusceptible to‑‑or at least distinct from‑‑”rational”
argument. This often characterizes a
taboo.
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Conclusion
The tradition of nonuse of nuclear weapons held throughout the conflict
in Vietnam. During the war, three U.S.
administrations progressively upped the level of violence, and engaged in
tremendously controversial policies, yet all drew the line at use of nuclear
weapons. Despite the enormous costs
and frustrations of the war, U.S. leaders avoided resort to the one thing that
might have “won” it—using tactical nuclear weapons.
We can distinguish
several different motivations for the nonuse of nuclear weapons in
Vietnam: first, fear of inadvertent
escalation, rooted in calculation about the risk of uncontrolled
escalation, plus the potential for an infinitely catastrophic outcome---the
dominant factor driving McNamara and others; second, preserving the tradition of nonuse, which Ball had emphasized; and
finally, a taboo, a normative belief that using nuclear weapons would be wrong.
It thus appears that the chances the
Johnson administration would have used nuclear weapons in Vietnam were nearly
zero, no matter what Generals Westmoreland, Sharp or Wheeler thought. In contrast, for Nixon and Kissinger––as for
Eisenhower earlier, less influenced by personal moral convictions––the taboo
operated primarily as an instrumental constraint on resort to nuclear
weapons. Although Nixon talked a tough
line, and sent notes to the North Vietnamese threatening massive use of force
if they did not agree to negotiate, in the end he and Kissinger were repeatedly
rolled back from their aspirations for knockout blows by domestic and world
public condemnation. They would have
been unable to use nuclear weapons without provoking the greatest outcry. Nixon probably did not personally share the
nuclear taboo––he did not think it was “wrong” to use nuclear weapons––but he
was constrained because others, including members of his own bureaucracy, held
it. As Kissinger later argued, “Never
had the military gap between a superpower and a nonnuclear state been greater;
never was it less likely to be invoked.”
How much did the taboo matter vis a
vis deterrence in explaining the nonuse of nuclear weapons in Vietnam? Soviet and Chinese nuclear forces may have
prevented any U.S. military thoughts of attacking Vietnamese sanctuaries inside
China, but they did not prevent thoughts of attacking southern China with
nuclear weapons in any expanded war.
The degree to which the United States could escalate the fighting inside
Vietnam was the most open question. Here, fear of a nuclear response by the
Soviet Union or China did not operate strongly for U.S. leaders. Rather, they worried about the more likely
possibility of a large-scale conventional war, its uncertain long-term
political and military consequences, and the more remote possibility of its
escalation to a nuclear war. Because
these calculations were uncertain, if no taboo on first use of nuclear weapons
existed, it is likely that military plans for their use would have been
considered much more seriously given the American––and conceivably even
Vietnamese––lives such use could have saved.
But it would be a mistake to draw
too sharp dichotomy between the force of the taboo and the force of escalation
risks, because they are not entirely independent. The existence of a weapons taboo helps to shape judgments of what
constitutes “escalation” on the battlefield.
If national leaders simply viewed tactical nuclear weapons as “just
another weapon,” the escalation effects of their use would likely have been
judged much less severely. Thus the
taboo, by helping to define what constituted escalation in the first place,
contributed to heightening decisionmakers’ perception of such risks during the
war.
What if
the United States had actually used nuclear weapons in Vietnam? From at least the time of the U.S. air strikes
in response to the events of the Tonkin Gulf in early August 1964, the North
Vietnamese leadership expected to be attacked with nuclear weapons. At that time, they sent women and children
to the countryside, and began to plan for casualties in the millions. At no time did they ever contemplate
surrender without unification with the South under Hanoi’s leadership and
ultimate control. This being so, it is
difficult to see how use of tactical nuclear weapons could have made the
slightest difference to the eventual outcome.
The North Vietnamese fully expected to be incinerated in large numbers,
and, if a nuclear attack occurred, they were prepared to persevere anyway.
The Vietnam case illustrates how,
ten years after the Korean war, despite the development in the interim of all
manner of small, low-yield, more “usable” nuclear weapons, they were less
usable than ever. Although concerns
about escalation clearly played a role in inhibiting their use, such concerns
were powerfully reinforced by political and normative considerations. By the time of the Vietnam War, the nuclear
taboo was operating with more powerful, widespread effects; it was becoming
less tentative, more taken-for-granted.
Further, the taboo itself became more firmly entrenched as a result of
the Vietnam War. Any remaining doubts
about whether the Korean War had been conducted correctly with respect to
nuclear weapons were laid to rest by Vietnam, which confirmed that even
tactical nuclear weapons were politically unusable. The war thus further eroded any lingering thoughts that nuclear
weapons could be viewed as legitimate weapons of war.
Even Henry
Kissinger was forced to confront the normative limitations on material
power. Although he had written a book
extolling the use of tactical nuclear weapons, he later drew away from
that. Once in the White House he found
to his regret that nuclear nations “could not necessarily use this power to
impose their will. The capacity to
destroy proved difficult to translate into a plausible threat even against
countries with no capacity for retaliation.” He attributed this to the awesomeness of the
destructive power of nuclear weapons.
But as Kissinger knew well, sub-kiloton weapons are not all that
awesome. So he was being a little disingenuous. But as the willingness of the North
Vietnamese to fight the United States illustrated, material power alone does
not make deterrence work. One of the
major lessons of Vietnam for students and practitioners of international
relations has been the normative and political limits on material power. Nowhere was this illustrated more clearly
than in the nonuse of nuclear weapons during the war.
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