A state seen as playing a major role in international politics. A great power possesses economic, diplomatic, and military strength and influence, and its interests extend beyond its own borders. The term is usually associated with the emergence of Austria, Russia, Prussia, France, and Great Britain as great powers in Europe after the Congress of Vienna in 1815; they worked together under a loose agreement known as the Concert of Europe. After World War I, the USA grew in importance, while after World War II, the USA and the Soviet Union, through their industrial strength, global influence, and nuclear capabilities, attained the status of “superpowers”, and world events became dominated by bipolarity. Since the collapse of the Soviet Union in 1991, the only superpower is the USA, though China’s growing economic and military strength may assure it superpower status in the next few years. The UK and France have declined from their former great power status, although they are still recognized by the United Nations Organization, together with the USA, Russia, and China, as permanent members of the United Nations Security Council with power of veto. The number of great powers at any time is considered a key feature of the international system, important in determining the level and nature of war.