Which theory asserts that no side would initiate a nuclear war if both could not survive its consequences?

The theory that asserts no side would initiate a nuclear war if both could not survive its consequences is known as Mutually Assured Destruction (MAD). This doctrine arose during the Cold War, when both the United States and the Soviet Union developed extensive nuclear arsenals. The central idea of MAD is that if two opposing sides possess enough nuclear weapons to ensure complete destruction of each other in the event of a nuclear strike, then both are deterred from actually launching an attack. They understand that initiating conflict would lead to catastrophic consequences not only for the enemy but also for themselves, thereby stabilizing the conflict through the logic of deterrence.

In the context of the other theories mentioned, Nuclear Strategy generally refers to a broader approach to nuclear deterrence and strategy, without specifically highlighting the principle of mutual destruction. Preemptive Strike Theory focuses on striking first when a threat is perceived, which does not align with the essence of deterrence that MAD presents. Collective Defense Theory typically involves alliances where nations agree to defend each other, primarily within conventional military contexts, rather than unilateral nuclear deterrence strategies. Hence, Mutually Assured Destruction uniquely encapsulates the concept that both parties would avoid initiating nuclear conflict due to the certainty of mutual annihilation.