The Single Integrated Operational Plan (SIOP) is a blueprint which specifies how American nuclear weapons would be used in the event of nuclear war. The first plan was developed in 1960, consisting of a list of targets ( National Strategic Target List) and the assets to be used against each target. This was extensively revised to become SIOP-62, a massive strike with the entire U.S. arsenal of 3,200 warheads against the USSR, China, and Soviet-aligned states. In 1963 the Kennedy administration revised the plan, resulting in SIOP-63-a strong counterforce strategy with a number of options in which the “no first use” policy became implicit. See also: