The diplomatic history of the United States oscillated among three positions: isolation from diplomatic entanglements of other (typically European) nations (but with economic connections to the world); alliances with European and other military partners; and unilateralism, or operating on its own sovereign policy decisions. This is in direct contrast to the European Union, whose member States have given up their national sovereignty in exchange for cooperative mediation and group policy-making, especially in the economic arena. Source: wikipedia