US Missile Development 1960s - '90s
The 1960s and 1970s saw widespread changes in the U.S. defensive missile force. Beginning in the mid-1960s the Army began to close many of its Nike installations, a move prompted in part by improved relations with the Soviet Union and also by the need to pay for America's rapidly escalating involvement in Southeast Asia.
But important technological changes were also at work. By the mid-1960s it became apparent that the Soviet Union was not going to build a large fleet of long-range bombers. Instead it focused on developing a large ICBM and submarine-launched ballistic missile (SLBM) force, and in doing so, rendered much of the U.S. air defense system obsolete. In an effort to regain the technological initiative, the Army experimented twice with developing an antiballistic missile (ABM) defense system, but the program was canceled shortly after the Anti-Ballistic Missile Treaty was signed in 1972.
The cancellation of the ABM program reflected the United States' realization that it could do little to defend itself against a Soviet ICBM attack other than to respond in kind. It was that grim logic that drove the Reagan administration to embrace the Strategic Defense Initiative during the 1980s. Despite the billions of dollars spent on the program, the end of the Cold War and the absence of a domestic consensus on the need for such a system led to its demise.
While defensive missile systems went into decline in the 1960s new and upgraded ICBMs continued to enter the inventory throughout the Cold War. Over time the missiles became progressively more powerful and more accurate, and their launch complexes better hardened to withstand a nuclear attack. By 1965 the Air Force had retired all its temperamental Atlas missiles and replaced the Titan Is with the improved Titan IIs. It had also deployed 800 of the new solid-fuel Minuteman missiles, each housed in an unmanned silo and ready to fire at a moment's notice.
Starting in 1966 the Air Force began upgrading the Minuteman force with the new Minuteman II. This missile had a longer range, a more accurate guidance system, and carried a more powerful warhead than its predecessor. Further improvements followed, and in 1971 the Air Force deployed its first Minuteman III. The new missiles were the first ICBMs to be fitted with multiple independently targetable reentry vehicles (MIRVs). Each missile carried three warheads, each accurate to within 800 feet.
The final installment in the Cold War ICBM program was the Peacekeeper or MX missile. Concerned over the increased size and accuracy of the Soviet ICBMs the Air Force explored nearly 40 basing schemes for its new ICBM, ranging from shuttling them over the southwest on railroad cars to basing them deep in the ocean floor. While the debate over the basing strategy raged in Congress, between 1986 and 1988 the Air Force installed 50 Peacekeepers in reconfigured Minuteman III silos. The new ICBM was a four-stage solid-fuel missile that carried ten warheads, each accurate to within 400 feet. The Air Force, however, was unable to devise a satisfactory basing strategy, and Congress canceled the Peacekeeper program after the first 50 missiles were deployed.