Atlanticism, also known as Transatlanticism, is the belief in or support for a close relationship between the United States and Canada, on one hand, and European countries on the other, regarding political, economic, and defence issues, in the belief that it would maintain the security and prosperity of the participating countries and protect the perceived values that unite them. The term derives from the Atlantic Ocean that separates North America from Europe. Atlanticism, also known as Transatlanticism, is the belief in or support for a close relationship between the United States and Canada, on one hand, and European countries on the other, regarding political, economic, and defence issues, in the belief that it would maintain the security and prosperity of the participating countries and protect the perceived values that unite them. The term derives from the Atlantic Ocean that separates North America from Europe. The term can be used in a more limited way to imply support for North Atlantic military alliances, or in a more expansive way implying broader cooperation, perceived deeply shared values, a merging of diplomatic cultures, and 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 through the establishment of various euro-Atlantic institutions, most importantly NATO and the Marshall Plan. Atlanticism varies in strength from region to region and country to country based on a variety of historical and cultural factors. It is often considered to be particularly strong in eastern and central Europe and the United Kingdom (linked to the Special Relationship). Politically, it has tended to be associated most heavily and enthusiastically, but certainly not exclusively, with classical liberals, or the political right in Europe. Atlanticism often implies an affinity for American political or social culture as well as the historical bonds between the two continents. There is some tension between Atlanticism and continentalism on both sides of the Atlantic, with some people emphasising increased regional cooperation or integration over trans-Atlantic cooperation. However, the relationship between Atlanticism and North American or European integration is complex, and they are not seen in direct opposition to one another by many commentators. Internationalism is the foreign policy belief combining both Atlanticism and continentalism. The relative decline of European power in the world, the fall of the Soviet Union, and the spread of Atlanticist norms outside of the North Atlantic region have decreased the strength of Atlanticist thought since the end of the Cold War. Other international relationships have been increasingly emphasised, although the trans-Atlantic relationship is still arguably the most important in the world. Prior to the World Wars, western European countries were generally preoccupied with continental concerns and creating colonial empires in Africa and Asia, and not relations with North America. Likewise, the United States was busy with domestic issues and interventions in Latin America, but had little interest in European affairs, and Canada, despite gaining self-governing dominion status through Confederation in 1867, had yet to exercise full foreign policy independence as a part of the British Empire. The experience of having American and Canadian troops fighting with British, French, and other Europeans in Europe during the World Wars fundamentally changed this situation. Though the US (and to some extent Canada) adopted a more isolationist position between the wars, by the time of the Normandy landings the Allies were well integrated on all policies. The Atlantic Charter of 1941 declared by US President Franklin D. Roosevelt and British Prime Minister Winston Churchill established the goals of the Allies for the post-war world, and was later adopted by all the Western allies. Following the Second World War, the Western European countries were anxious to convince the US to remain engaged in European affairs to deter any possible aggression by the Soviet Union. This led to the 1949 North Atlantic Treaty which established the North Atlantic Treaty Organization, the main institutional consequence of Atlanticism, which binds all members to defend the others, and led to the long-term garrisoning of American and Canadian troops in Western Europe. After the end of the Cold War, the relationship between the United States and Europe changed fundamentally, and made both sides less interested in the other. Without the threat of the Soviet Union dominating Europe, the continent became much less of a military priority for the US, and likewise, Europe no longer felt as much need for military protection from the US. As a result, the relationship lost much of its strategic importance. Atlanticism has undergone significant changes in the 21st century in light of terrorism and the Iraq War, the net effect being a renewed questioning of the idea itself and a new insight that the security of the respective countries may require alliance action outside the North Atlantic territory. After the September 11, 2001, attacks, NATO for the first time invoked Article 5, which states that any attack on a member state will be considered an attack against the entire group of members. Planes of NATO's multi-national AWACS unit patrolled the U.S. skies and European countries deployed personnel and equipment. However, the Iraq War caused fissures within NATO and the sharp difference of opinion between the US-led backers of the invasion and opponents strained the alliance. Some commentators, such as Robert Kagan questioned whether Europe and the United States had diverged to such a degree that their alliance was no longer relevant.