The Cold War was the most clear-cut case of bipolarity in modern history. Polarity, in international relations, refers to the number of states or groups of states that have important amounts of power in the international arena. During the Cold War, there were two clear blocs of states with obvious leaders. These were the democratic countries, with the United States as their acknowledged leader, and the communist countries, almost all of which were really satellite states of the Soviet Union. Although some other countries tried to make themselves relevant as the nonaligned movement, they never had enough power to make themselves an important “pole” in the international system. This was most definitely an era of bipolarity in the world.
Because the world was bipolar and because the blocs’ leaders exerted so much power, this was a time when the structure of international relations was somewhat less anarchic than it usually is. Both the United States and the Soviet Union were able to exert a great deal of power over their allies/clients. This meant that there were two centers of power that could create a fair amount of stability within their respective spheres of influence. The Cold War, then, was a highly bipolar era in international relations with two blocs whose leaders were able to maintain a high level of order among their allies and clients.