Unipolar balances of power are international political systems where one major power dominates the globe. They are traditionally seen as more stable than are bipolar systems, where two powerful superpowers are locked in conflict and use weaker states in their mutual power plays. Multipolar systems, as existed in Europe the period before World War I, are seen as the most volatile and unstable balances of power.

             However, unipolar systems are not always more stable-the United States may be the major superpower of the immediate post-Cold War period, yet small ethnic conflicts were rife after the end of the Cold War. The period between 1945-1990 is often characterized as bipolar, because of the tensions of the Cold War period that divided the 'free' and communist spheres. Other scholars call it unipolar, in the sense that one major conflict dominated the globe to all others.

             There was a complex dynamic between the two major powers of the United States and the Soviet Union during this period. Not all conflicts in the world were between the superpowers, but the superpowers attempted to become involved in all regional conflicts. For example, the Vietnamese communist forces of Ho Chi Minn saw themselves as nationalist forces, rather than allied with the Soviet Union, yet the U.S. still felt compelled to intervene. China was alienated from the USSR but was still a communist power. France disassociated itself from NATO, the primary alliance of the West, and was contemned by the U.S. and the Islamic world was divided between religions rather than politics, although the Soviet Union attempted to support anti-Israeli forces. However, despite these multipolar displays of regional conflict, both superpowers claimed an interest in virtually every world conflict, stretching from Latin America to Asia, and reduced these conflicts to their ideological terms, in their own worldviews.

             Thus, the period could be characterized as bipolar because of the two powers involved, or unipolar in terms of the singular focus of its conflict between communist-supported and American-supported powers.