NATO has taken on missions beyond Europe since the Cold War ended, including in Afghanistan. After 9/11, NATO invoked its collective defense clause and took command of the International Security Assistance Force in Afghanistan in 2003, its first mission outside of Europe. At its height, NATO commanded over 130,000 troops from 50 allied countries in Afghanistan. NATO completed its Afghanistan mission in 2014 but remained to provide training and assistance until withdrawing all remaining forces in 2021, ending its 20-year involvement.