29 is the new number of NATO Nations. With Montenegro joining the Alliance, the North Atlantic Treaty Organization has enlarged for the first time since 1 April 2009. The Joint Force Training Centre, as well as other NATO headquarters, welcomed the new member state by raising its flag on 7 June.

Montenegro became NATO’s latest member on 5 June 2017. Allied Foreign Ministers signed Montenegro's Accession Protocol in May 2016 and later all 28 national parliaments voted on ratification of Montenegro's membership. The Montenegrin parliament ratified the accession treaty on 28 April 2017.

Montenegro joined the Partnership for Peace (PfP) in December 2006 - shortly after regaining its independence in June 2006. In December 2009, the country was invited to join the Membership Action Plan and six years later - to start accession talks to join the Alliance.

Montenegro actively supported the NATO-led operation in Afghanistan from 2010 to the end of 2014 and is now supporting the follow-on mission to train, advise and assist the Afghan security forces.