section_path: History/21st century
section_name: 21st century
paragraph_text: 21st century
  
  Article 5 of the North Atlantic treaty, requiring member states to come to the aid of any member state subject to an armed attack, was invoked for the first and only time after the September 11 attacks, after which troops were deployed to Afghanistan under the NATO-led ISAF. The organization has operated a range of additional roles since then, including sending trainers to Iraq, assisting in counter-piracy operations.
  
  The election of French president Nicolas Sarkozy in 2007 led to a major reform of France's military position, culminating with the return to full membership on 4 April 2009, which also included France rejoining the NATO Military Command Structure, while maintaining an independent nuclear deterrent.
  
  The 2014 Russia's annexation of Crimea led to strong condemnation by all NATO members, and was one of the seven times that Article 4, which calls for consultation among NATO members, has been invoked. Prior times included during the Iraq War and Syrian Civil War. At the 2014 Wales summit, the leaders of NATO's member states formally committed for the first time to spend the equivalent of at least two percent of their gross domestic products on defence by 2024, which had previously been only an informal guideline.
  
  At the 2016 Warsaw summit, NATO countries agreed on the creation of NATO Enhanced Forward Presence, which deployed four multinational battalion-sized battlegroups in Estonia, Latvia, Lithuania, and Poland. Before and during the 2022 Russian invasion of Ukraine, several NATO countries sent ground troops, warships and fighter aircraft to reinforce the alliance's eastern flank, and multiple countries again invoked Article 4. In March 2022, NATO leaders met at Brussels for an extraordinary summit which also involved Group of Seven and European Union leaders. NATO member states agreed to establish four additional battlegroups in Bulgaria, Hungary, Romania, and Slovakia, and elements of the NATO Response Force were activated for the first time in NATO's history.
  
  As of June 2022, NATO had deployed 40,000 troops along its 2,500-kilometre-long (1,550 mi) Eastern flank to deter Russian aggression. More than half of this number have been deployed in Bulgaria, Romania, Hungary, Slovakia, and Poland, which five countries muster a considerable combined ex-NATO force of 259,000 troops. To supplement Bulgaria's Air Force, Spain sent Eurofighter Typhoons, the Netherlands sent eight F-35 attack aircraft, and additional French and US attack aircraft would arrive soon as well.