Operation Eagle Assist began following the September 11 attacks on October 9, 2001, after the North Atlantic Council's October 4 decision to operationalize Article 5 of the North Atlantic Treaty. In total, 830 crew members from 13 NATO nations executed 360 operational sorties, totaling nearly 4300 hours, over the skies of the United States in NATO AWACS aircraft. The operation ended on May 16, 2002.