By the end of World War II, the multi-polar international system characterized by the pursuit of the balance of power among great powers, in a way that none of them was strong enough to predominate over others, transformed in bipolarity. The bipolar world was dominated by two opposite great powers with strong economic, military, and cultural influence on their allies. This nearly equal amount of distribution of power between the United States and the Union of Soviet Socialist Republics created an international system with no peripheries and with two different spheres of influence which resulted in stability for more than 40 years and assured peace between the two great powers and limited wars in the rest of the world. After the collapse of the USSR and the end of the Cold War, the US emerged as the only great power of a new unipolar international system.
