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
In 1949 Sweden chose not to join NATO and declared a security policy aiming for non-alignment in peace and neutrality in war. A modified version now qualifies non-alignment in peace for possible neutrality in war. This position was maintained without much discussion during the Cold War. Since the 1990s however there has been an active debate in Sweden on the question of NATO membership in the post–Cold War world. These ideological divides were visible in November 2006 when Sweden could either buy two new transport planes or join NATO's plane pool, and in December 2006, when Sweden was invited to join the NATO Response Force. Sweden have been active participants in NATO-led missions in Bosnia (IFOR and SFOR), Kosovo (KFOR), Afghanistan (ISAF), and Libya (Operation Unified Protector).