The United States as Global Power

International relations scholars generally define "great power" status through a combination of material capabilities and social recognition. Material criteria include military strength, economic output, population, technological capacity, and the ability to project power beyond one's borders; recognition refers to whether other states treat an actor as a great power in diplomacy and institutions, such as permanent membership on the United Nations Security Council. Realist scholars such as John Mearsheimer emphasize that great powers are those with sufficient military capability, particularly land power, to plausibly contend for regional or global dominance. Historically, the Concert of Europe that followed the Congress of Vienna in 1815 grouped Britain, Austria, Prussia, Russia, and later France as recognized great powers managing continental order; the pre-1914 system was multipolar, the Cold War (1947-1991) was bipolar around the United States and the Soviet Union, and the post-1991 period has been debated as unipolar, and more recently as trending toward multipolarity.