The State Union of Serbia and Montenegro applied to NATO's Partnership for Peace (PfP) program in June 2003.

In November 2007, Montenegro signed a transit agreement with NATO, allowing the alliance's troops to move across the country.

[10] Montenegro entered Intensified Dialogue with NATO in April 2008, and adopted an Individual Partnership Action Plan in June 2008.

[12][13] The country then applied for a Membership Action Plan on 5 November 2008 with support of Prime Minister Milo Đukanović,[14] which was granted in December 2009.

[18] The country deployed 40 soldiers, a three-member military medical team, and two officers under German command to Afghanistan in 2010.

[19] Montenegro has received support for its membership bid from several NATO countries, including Romania, Turkey, Germany and the United States.

Analysts confirmed this as a sign that NATO members are becoming skeptical about further Eastern expansion following Russia's annexation of Crimea, due to worries about Russian retaliation to new security guarantees to countries so close to its borders.

[1] The reaction of the Russian government to Montenegro's bid to join NATO had been increasingly hostile[40] culminating in an attempt to stage a coup d'état on 16 October 2016, on the day of the parliamentary election that allegedly would have included assassination of Montenegro's prime minister Milo Đukanović, according to the statements made by Montenegrin officials.

In early 2009 they launched a two-year campaign with the aim of promoting accession to NATO, which is handled by the MAPA media agency under theatrical director Radmila Vojvodić.

[49] The ruling coalition of PM Milo Đukanović claims Montenegro cannot afford to remain neutral and identifies NATO and the EU as a common process of Euro-Atlantic integrations.

[50] According to a demographic breakdown of polling, citizens of pro-Serbian or pro-Russian political orientation, Eastern Orthodox Christian conservatives, women and the undereducated are the main groups that do not support NATO membership.

SNP CG has generally avoided giving a direct answer, but it is indirectly opposed to NATO membership.

[citation needed] The New Serb Democracy is an outspoken opponent of NATO membership, supporting a referendum and convinced there would be a negative outcome.

[57] A political crisis followed the government's announcement of intention to join NATO; large protests, supported by pro-Serbian parties, were held in Podgorica in mid-October 2015 that culminated in a riot in the capital on 24 October.