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.
Ukraine
Following independence, Ukraine declared itself a neutral state. The country has had a limited military partnership with Russian Federation, other CIS countries and a partnership with NATO since 1994. In the 2000s, the government was leaning towards NATO, and a deeper cooperation with the alliance was set by the NATO-Ukraine Action Plan signed in 2002. It was later agreed that the question of joining NATO should be answered by a national referendum at some point in the future. Recently deposed President Viktor Yanukovych considered the current level of co-operation between Ukraine and NATO sufficient, and was against Ukraine joining NATO. During the 2008 Bucharest summit, NATO declared that Ukraine would eventually become a member of NATO when it meets the criteria for the accession.