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.
Enlargement of NATO
NATO has added new members seven times since its founding in 1949 to include twenty-nine members. Twelve countries were part of the founding of NATO: Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom, and the United States. The early years of the Cold War saw a stark divide between Capitalist states, backed by United States, and Communist satellite states of the Soviet Union. This divide eased inclusion of Portugal under Salazar in NATO and encouraged the anti-Communist governments of Greece and Turkey to join NATO in 1952. Greece would suspend its membership in 1974, over the Turkish invasion of Cyprus, but rejoined in 1980 with Turkey's cooperation.