Since the beginning of the cold war the keystone of American strategic planning has been the principle that the ultimate deterrent to a Russian attack had to be the certainty of American retaliation against Russian cities. The Russians seemingly have adopted the same position vis-à-vis the United States, usually to the point of denying vigorously any possibility of limiting central war to counterforce strikes alone. A typical formulation was expressed by former Defense Secretary McNamara in his 1968 “posture statement” to Congress:

[It is] the clear and present ability to destroy the attacker as a viable 20th Century nation and an unwavering will to use those [Assured Destruction] forces in retaliation to a nuclear attack upon ourselves or our allies that provides the deterrent, and not the ability partially to limit damage to ourselves.