STRAT-X
STRAT-X, or Strategic-Experimental, was a U.S. government-sponsored study conducted during 1966 and 1967 that comprehensively analyzed the potential future of the U.S. nuclear deterrent force. At the time, the Soviet Union was making significant strides in nuclear weapons delivery, and also constructing anti-ballistic missile defenses to protect strategic facilities. To address a potential technological gap between the two superpowers, U.S. Secretary of Defense Robert McNamara entrusted the classified STRAT-X study to the Institute for Defense Analyses, which compiled a twenty-volume report in nine months. The report looked into more than one hundred different weapons systems, ultimately resulting in the MGM-134 Midgetman and LGM-118 Peacekeeper intercontinental ballistic missiles, the Ohio-class submarines, and the Trident submarine-launched ballistic missiles, among others. Journalists have regarded STRAT-X as a major influence on the course of U.S. nuclear policy.
Background
In the mid-1960s, reports received by U.S. intelligence agencies indicated that the Soviets were planning to deploy large numbers of highly accurate and powerful intercontinental ballistic missiles (ICBMs). Later, the R-36 ICBM entered service. Possessing the greatest throw weight of any ICBM ever at 8.8 tonnes (19,000 lb), the R-36 was larger than the most modern ICBMs in the U.S. arsenal at the time. Due to its size, it was able to carry high-yield warheads capable of destroying Minuteman hardened silos (see Counterforce). This was considered a significant risk to American ICBMs and, as a result, to the United States' nuclear defense strategy by reducing the United States' ability to retaliate with nuclear weapons if attacked.