The organization now plays a prominent role in Afghanistan after the September 11 attacks in the United States invoked Article 5 of the North Atlantic Treaty which deemed the attacks to be an external attack on all NATO members under the idea of collective defence. Aside from continuing efforts in Afghanistan NATO has participated in a wide range of roles including relief effort, counter-piracy, enforcing no-fly zones and naval blockades.
NATO was prominent in Bosnia during the early 1990s, and gradually its role became larger with some operations escalating, for instance Operation Sky Monitor turned into Operation Deny Flight which gave NATO "all measures necessary" to enforce a more stringent no-fly zone unlike Sky Monitor during which the no-fly zone was violated over 500 times. It took 46 years after NATO's inception in 1949 for the organization first ever military intervention took place in 1995, Operation Deliberate Force which was targeted the Army of Republika Srpska in Bosnia whose presence posed a danger to designated United Nations "safe areas". The air campaign helped bring about the Dayton Accords.
On 20 December 2001, UN Security Council Resolution 1386 unanimously approved the International Security Assistance Force, a multi-national NATO-led coalition with the aim of enforcing peace in Afghanistan.
ISAF ceased combat operations in 2014, with a minority of troops remaining behind as the advisory Resolute Support Mission.