Although the North Atlantic Treaty Organization (NATO) existed as an alliance and conducted joint military exercises throughout the Cold War period, it engaged in no military operations during this time. All of its military operations occurred in the post-Cold War era. The first of these was in Bosnia, where NATO engaged to an increasing extent. This engagement culminated in NATO's 1995 air campaign, Operation Deliberate Force, which targeted the Army of Republika Srpska, whose presence in Bosnia posed a danger to United Nations Safe Areas. This engagement ultimately helped to bring about the Dayton Accords.
The organization played a prominent role in Afghanistan after the September 11 attacks, when the United States invoked Article 5 of the North Atlantic Treaty, which interprets an external attack on any member to be an attack on all NATO members under the idea of collective defense. NATO has participated in a wide range of roles elsewhere, including relief efforts, counter-piracy, enforcing no-fly zones and naval blockades.
