Since the Alliance’s creation in 1949, Article 4 has been invoked seven times. On 24 February 2022, Bulgaria, Czechia, Estonia, Latvia, Lithuania, Poland, Romania and Slovakia requested to hold consultations under Article 4 following the Russian invasion of Ukraine.
On 26 July 2015, Türkiye made the same request in view of the seriousness of the situation following terrorist attacks, and to inform Allies of the measures it was taking. Poland invoked Article 4 on 3 March 2014 following increasing tensions in neighbouring Ukraine, as a result of Russia’s aggressive actions. On two occasions in 2012, Türkiye requested a NAC meeting under Article 4: once on 22 June after one of its fighter jets was shot down by Syrian air defence forces and the second time on 3 October when five Turkish civilians were killed by Syrian shells. Following these incidents, on 21 November, Türkiye requested the deployment of Patriot missiles. NATO agreed to this defensive measure so as to help Türkiye defend its population and territory, and help de-escalate the crisis along the border.