For decades, nuclear arms control negotiations moved slowly and generated little in the way of real disarmament. The first breakthrough was the 1987 treaty on Intermediate-range Nuclear Forces (INF), which obligated the United States and the Soviet Union to eliminate an entire class of missiles and missile launchers. The eighteen-month period beginning with the signing of the first Strategic Arms Reduction Treaty (START I) in July 1991 and ending with the signing of the second START accord (START II) in January 1993 constituted an even more significant watershed. These two agreements, in conjunction with several unilateral initiatives undertaken during this period by Washington and Moscow, obliged the United States and Russia to reduce their inventories of deployed strategic and tactical nuclear weapons by over 70 percent. In addition, Washington and Moscow took steps to enhance nuclear stability, reduce the dangers posed by accidental launches and unauthorized attacks, slow down nuclear modernization, and strengthen verification mechanisms.
Important progress has also been made in multilateral efforts to control nuclear proliferation. China and France signed the Nuclear Non-Proliferation Treaty (NPT) in 1992, and the NPT was extended indefinitely at its May 1995 review conference. Efforts to conclude a Comprehensive Test Ban Treaty (CTBT) and a ban on production of fissile material for military purposes have moved forward.
Encouraged by these developments and spurred by the dangers posed by existing nuclear arsenals and nuclear proliferation,scholars, analysts, and policymakers have started to take a harder look at the possibilities for complete, global nuclear disarmament. Many believe that eliminating nuclear weapons from the face of the planet is a highly desirable long-term objective. The Stimson Center’s Project on Eliminating Weapons of Mass Destruction has taken a pragmatic approach to this issue, arguing that if nuclear disarmament is to come about, it will probably do so through a step-by-step process that will unfold over a long period of time-perhaps decades. The Project’s Steering Committee envisages a four-step process: during Phase I, the United States and Russia would reduce their strategic arsenals to no more than 2,000 weapons each; during Phase II, the five declared nuclear weapon states (the United States, Russia, China, France, and Britain) would agree to reduce their arsenals to or cap their arsenals at no more than several hundred weapons each; during Phase III, all nuclear weapon states would reduce their arsenals to or cap their arsenals at no more than several dozen weapons each; during Phase IV, all nuclear weapons would be eliminated.
This paper explores the implications of phased reductions in nuclear forces for US defense policy. First, it identifies and analyzes the main strategic conditions that would have to be met, particularly from the standpoint of US policymakers, before each of these steps could be taken. It then discusses the impact these steps would have on US defense policy, focusing in particular on the changes that would have to take place in US military strategy, US nuclear doctrine, the US nuclear force structure (strategic offensive forces, strategic defenses, and tactical nuclear capabilities), US conventional forces, and the US ability to extend deterrence to key allies in Europe, Asia, and the Middle East. Third, it makes some broad assessments about the risks each of these disarmament steps would pose to US national security.