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.
Foreign relations of NATO
Armenia has maintained positive relations with NATO members and has signed up for the Partnership for Peace programme, the Euro-Atlantic Partnership Council and the Individual Partnership Action Plan. However, Armenia is unlikely to join NATO as its policies often align it closer with Russia, and it remains a member of the Commonwealth of Independent States and the Collective Security Treaty Organization. Armenia pulled out of its participation in NATO military exercises in Georgia on 8 May 2009, because of NATO's Secretary-General's alleged support of Azerbaijan, possibly making it even less likely that Armenia will eventually join NATO.