2001 NATO Article 5 contingency

The North Atlantic Treaty Organization (NATO) declared an Article 5 contingency through a series of resolutions of the North Atlantic Council enacted between September 12 and October 2, 2001, done in response to the September 11 attacks in the United States. The decision to invoke NATO's collective self-defense provisions was undertaken at NATO's own initiative, without a request by the United States, and occurred despite the hesitation of Germany, Belgium, Norway, and the Netherlands. It is the only time in NATO's history its collective defense provisions have been invoked.

Two small military operations were ultimately authorized under the terms of the resolutions: Operation Eagle Assist, consisting of the deployment of several aircraft to North America; and, Operation Active Endeavour, a mostly symbolic naval deployment in the Mediterranean Sea. The United States, which was skeptical of NATO capabilities, elected not to seek further Article 5 support and the alliance did not participate in the ensuing American invasion of Afghanistan, though some individual members did make contributions outside of the NATO command structure.

In response to a request by the United Nations, NATO later raised and deployed the International Security Assistance Force (ISAF) with the objective of stabilizing Afghanistan following the United States invasion of that country. ISAF itself was composed mostly of U.S. forces and was headed by U.S. commanders.

Background

On the morning of September 11, 2001, several civilian and military targets in the United States were damaged and destroyed by Al-Qaeda forces. At the time of the September 11 attacks, it was believed by some that the co-occurring 2001 anthrax attacks were also linked to Al-Qaeda.

The United States is a member of the North Atlantic Treaty Organization (NATO).