Following World War II, the world became polarized in a cold war between two superpowers, the United States and the Soviet Union. The realist perspective list several possible reasons for this standoff: perhaps the Cold War began because of Soviet aggression, or perhaps because of the expansionist nature of the U.S. capitalist system, or perhaps it began simply because the international security dilemma left the two countries no other viable option. Whatever the reason, realists argue that the United States won the Cold War by means of deterrence and an arms race that bankrupted the Soviet Union.

The liberal perspective, focusing on institutions and diplomacy, attributes the origin of the Cold War to the UN’s failure to establish collective security; the Cold War’s end came about through the slow process of communication, negotiations, and détente, characterized by agreements like the Helsinki Accords.

For the identity perspective, the Cold War was about values and common humanity, and they point to the nature of American democracy and Marxist-Leninism as the origins of the conflict. Accordingly, it came to an end only when the two superpowers’ ideologies became less divergent. The identity perspective emphasizes the effect leaders such as Gorbachev and Reagan had on deconstructing the Cold War.

Finally, critical theorists argue that the Cold War was an inevitable manifestation of the social and political revolution associated with communism and capitalism.