Enlargement of NATO
As of 2018, NATO officially recognizes four aspiring members: Bosnia and Herzegovina, Georgia, Macedonia and Ukraine. The Federation of Bosnia and Herzegovina within Bosnia and Herzegovina has expressed willingness to join NATO, however, it faces consistent political pressure from Republika Srpska, the other political entity in the country, alongside its partners in Moscow. Macedonia has been prevented from joining the alliance by Greece, one effect of the Macedonian naming dispute. Future expansion is currently a topic of debate in several countries outside the alliance, and countries like Sweden, Finland, and Serbia have open political debate on the topic of membership, while in countries like Ukraine, support and opposition to membership is tied to ethnic and nationalist ideologies. The incorporation of countries formerly part of the Eastern Bloc and the Soviet Union has been a cause of increased tension between NATO countries and Russia.
Canada–NATO relations
Canada has been a member of the North Atlantic Treaty Organization (NATO) since its inception in 1949. Canada was not only a member but one of the principal initiators (founding countries) of the alliance. This Atlanticist outlook was a marked break with Canada's pre-war isolationism, and was the first peacetime alliance Canada had ever joined. However, Canadian officials such as Hume Wrong and Lester B. Pearson and including Prime Minister Louis St. Laurent worked in favour of the alliance not only because they sought to contain the Soviet Union, as did other members, but because they hoped the treaty would help to eliminate any potential rivalries between the United States, the United Kingdom, and other European great powers (principally at the time France, but later including West Germany), where Canada would be forced to choose sides. This had long been the overriding goal of Canadian foreign policy. The main Canadian contribution to the North Atlantic Treaty was Article 2 which committed members to maintain a "free" political system and to promote economic cooperation, in addition to the more usual diplomatic and military matters. However trans-Atlantic unity in political and economic matters has not come to fruition, as European states have looked toward the European Union and its antecedents while North America has the North American Free Trade Agreement