Atlanticism

thumb|US government poster promoting the Marshall Plan (1950) Atlanticism, also known as Transatlanticism or North Atlanticism, is the ideology which advocates a close alliance between nations in Northern America (the United States and Canada) and in Europe on political, economic, and defense issues. The term derives from the North Atlantic Ocean, which is bordered by North America and Europe. It is a geopolitical ideology in the same regard as Eurasianism or Gulfism.

The term can be used in a more specific way to refer to support for North Atlantic military alliances against the Soviet Union, or in a more expansive way to imply broader cooperation, perceived deeply shared values, a merging of diplomatic cultures, as well as a sense of community and some degree of integration between North America and Europe. In practice, the philosophy of Atlanticism encourages active North American, particularly American, engagement in Europe and close cooperation between states on both sides of the ocean. Atlanticism manifested itself most strongly during the Second World War and in its aftermath, the Cold War, through the establishment of various Euro-Atlantic institutions, most importantly NATO and the Marshall Plan, with the purpose being to maintain or increase the security and prosperity of the participating countries during the Cold War and protect liberal democracy.