From Vietnam to the New Triad: U.S. Nuclear Weapons and Korean Security

Willis Stanley
Director of Regional Studies, National Institute for Public Policy, 2003.

The JASON study of Tactical Nuclear Weapons in Southeast Asia essentially finds that, no matter how gently you tap, it is not wise to use a hammer to screw in a light bulb. In short, S-266 provides sufficient insight to conclude that in 1967, tactical nuclear weapons were not the tool most appropriate for the job of closing the supply routes between North and South Vietnam.

But what do Dyson et al's findings say about the utility of tactical nuclear weapons in 2003, in locales other than Vietnam? Alas, the JASONs found no universal truth in the brief pages of S-266 and we must look to the unique circumstances of any present-day case in order to make similar judgments. More importantly, we should not limit ourselves to assessing the utility of the Cold War nuclear force for the post-Cold War world-we should focus on how to best adapt and transform that force to meet the challenges of today and tomorrow. Today's situation on the Korean peninsula is indicative of trends that will shape how we approach the future utility of nuclear weapons.

The Democratic Peoples Republic of Korea (DPRK or North Korea) is poised, not for a war of attrition using irregular forces like the Viet Cong, but for a lightning strike that leaves them in possession of the peninsula in a matter of weeks. Supporting that intent is the forward deployment of a vast conventional force and (at least) chemical weapons. The DPRK has amassed an imposing military force over 1 million persons strong with a reserve of over 7 million. Over seventy percent of the DPRK's active duty ground troops are stationed within about 145 kilometers of the Demilitarized Zone (DMZ) that separates North and South. More worrisome are the DPRK's estimated 12,000 artillery tubes and 2,300 multiple rocket launchers that, from their current emplacements, are capable of raining 500,000 shells per hour on U.S. and South Korean troops. 500 long-range artillery pieces are able to target Seoul, a mere 40 kilometers from the DMZ.

To further complicate the threat picture, North Korea has constructed an elaborate array of underground facilities. In 1963, North Korean dictator Kim Il-sung stated "…we must dig ourselves into the ground to protect against the threat of atomic bombs." According to a U.S. Department of Defense estimate, much of the DPRK's forward-based force is protected by over 4,000 underground facilities in the forward area alone. There are even tunnels that the DPRK has constructed under the DMZ to rapidly insert forces behind the defenders. U.S. and South Korean forces might have as little as 24 hours warning if North Korea invaded from this forward-leaning posture. The attack would likely not only devastate Seoul, but would include attempts to strike targets throughout South Korea using missiles, aircraft and special operations forces (North Korea has the largest special operations force in the world). These attacks would likely utilize chemical and perhaps biological agents to sow chaos and degrade Combined Forces operations. It is possible that even U.S. bases in Japan could suffer such attacks.

Under these conditions, a North Korean assault would resemble less the irregular, protracted fight in Vietnam than the scenario in which the JASONs suggest that tactical nuclear weapons would have a "decisive effect:" "a Chinese 'horde,' a million strong, walking into Southeast Asia." In 1967, the same year S-266 was published, the U.S. nuclear force deployed in South Korea reached its peak of approximately 950 warheads. These forces were not unique; the period saw extensive forward deployment of U.S. nuclear forces around the globe. According to The Bulletin of the Atomic Scientists, those numbers had dropped to around 150 by the mid-1980s. U.S. nuclear weapons were gone entirely from the peninsula by 1992. Despite the absence of forward deployed weapons, current U.S. and South Korean officials continue to stress that North Korea will suffer the "gravest consequences" should the DPRK employ weapons of mass destruction (WMD).

Given the observations above, why do present circumstances not require a robust forward deployed U.S. tactical nuclear capability to deter or defeat a DPRK invasion force, much as U.S. nuclear forces contributed to deterring a conventional Warsaw Pact attack on Western Europe? First, and foremost, the conventional forces available to the United States and South Korea are superb and generally assessed as capable of dealing with the threat without WMD. Second, the "grave consequences" of nuclear weapons deployed from bases in the United States provide some "nuclear credibility" that "Dear Leader" Kim Jong-il cannot afford to ignore. Indeed, his pursuit of long-range missiles capable of delivering a nuclear-sized payload to the United States demonstrates that he recognizes the deterrent power of global strike capabilities and seeks to trump similar U.S. reach. Third, given the conventional might at the disposal of the Combined Forces Command (CFC), any advantage to be gained by using nuclear weapons would be offset by the prodigious operational difficulties imposed by use of the existing nuclear arsenal. For example, nuclear weapons could be used to stall second and third echelon DPRK forces or to try digging artillery tubes out of their fortified sites. However any nuclear use would have to account not only for friendly military forces but also for: the millions of civilians living proximate to the DMZ (i.e., Seoul and its suburbs); the avenues of counterattack; and Korea's neighboring countries.

Are nuclear weapons, then, irrelevant for the defense of South Korea? Unfortunately not. The United States considered the use of nuclear weapons to prevent a rout of UN forces on the peninsula during the Korean War. While most assessments hold that today's CFC is capable of turning back Kim Jong-il's tide, war is an inexact, non-linear business. At some point, it remains possible that an American President's only option to avoid catastrophic loss of life might be to authorize nuclear use to halt the advance of the DPRK forces. Other circumstances in which nuclear use might be considered include U.S. discovery of the need for prompt, certain kill of a DPRK WMD-armed ballistic missile preparing for launch against Tokyo or perhaps even Anchorage. Surprises about the size and scope of the DPRK WMD and missile capabilities could also change U.S. operational plans to emphasize the need to defeat certain target types that currently are only vulnerable to nuclear attack, for example, mobile strategic targets and hard underground facilities. The possible implications of such a surprise mean that U.S. planners cannot in good conscience rule out an option that may be the lesser of two very evil choices.

These problems are at the heart of the Bush administration's approach to nuclear strategy as described in public discussions of the recent Nuclear Posture Review. In the post-Cold War world, including Korea, the barrier the JASONs saw between tactical and strategic nuclear forces has crumbled. In that context, an American nuclear deterrent structured to face a "strategic" foe already vanquished (i.e., the Soviet Union) runs the risk of being an expensive and cumbersome irrelevance. Resolving this issue is at the heart of the New Triad of U.S. strategic forces which will now include active and passive defenses, conventional strike options, and a defense infrastructure charged with being responsive to changes in the threat posed by, to borrow a phrase from S-266, "ruthless and irresponsible" regimes.

Adapting to the world of the New Triad will mean U.S. pursuit of conventional capabilities to attack targets now only vulnerable to the nuclear arsenal. It will also mean that we need to explore ways to make our nuclear capabilities fit less onerously in the unique niches that our conventional strategic forces as yet cannot address. That means: exploring the potential for earth penetrating warheads more capable than the current B61-11; investigating the potential for adapting existing weapons designs to address new missions; studying the costs and risks of a new generation of low yield "micro" and "mini" nuclear weapons; and most importantly, finding credible, effective conventional strike options to minimize the need for a U.S. President to consider nuclear use. These steps describe some of what is required to make our future strategic posture credible and relevant to the new post-Cold War environment-and that is an important part of maintaining peace and security on the Korean peninsula.

Willis Stanley
Director of Regional Studies
National Institute for Public Policy
3031 Javier Rd. Ste. 300
Fairfax, VA 22031
Phone: 703-598-0563
FAX: 703-698-0566

Willis Stanley has extensive experience in the areas of deterrence, missile proliferation, arms control, grand strategy, military-technical affairs, and the impact of all of the above on U.S. political and military strategy and policy. Mr. Stanley is a contributor to National Institute's study titled Rationale and Requirements for U.S. Nuclear Forces and Arms Control.