A theory which states that nuclear weapons can in fact increase stability within the international system and decrease the chances of crisis escalation. Nuclear weapons are credited with having induced the stability throughout the Cold War. Because both the U.S. and the Soviet Union possessed second-strike capability, the possibility of a nuclear victory for either side was eliminated. Thus, both sides optioned for the non-use of nuclear weapons.

Opposition to the theory believe that an increase in nuclear states will increase the opportunity for nuclear weapons to fall into the wrong hands. Nuclear peace theory relies on leaders acting rationally, however if a leader is irrational nuclear weapons will be very dangerous under their control.