 Thors were kept positioned and active near the two Johnston Island launch pads after 1964.However, partly because of the Vietnam War, in October 1970 the Department of Defense had transferred Program 437 to standby status as an economic measure.The Strategic Arms Limitation Talks led to Anti-Ballistic Missile Treaty that prohibited 'interference with national means of verification', which meant that ASAT's were not allowed, by treaty, to attack Russian spy satellites.