After spending more than $70 billion over three decades on more or less urgent research and development, the United States appears finally to be moving toward the deployment of a ballistic missile defense (BMD) system. It will consist of interceptor missiles and sensors designed to protect all fifty states from a small long-range ballistic missile attack. Such a system, now called National Missile Defense (NMD), has been the subject of fierce debate in Washington in three distinct periods: first in the late 1960s and early 1970s, again in the latter half of the 1980s, and finally since the mid-1990s.
Of these three debates, the most heated polemics followed Ronald Reagan’s 1983 announcement of the Strategic Defense Initiative (or SDI, pejoratively dubbed “Star Wars” by Senator Edward Kennedy). The SDI debate, however, did little more than restate the positions for and against NMD that had first been raised during the earlier debate of the 1960s, and both these debates concluded with decisive policy decisions against NMD deployment. Despite various points during those years when a decision for NMD appeared plausible, the political consensus necessary for deployment could not be sustained. Throughout this thirty-year period, therefore, the United States consciously chose not to deploy NMD, preferring instead to rely almost exclusively on deterrence to protect the American people against the threat of intercontinental missile attack.