What is NATO?

The North Atlantic Treaty Organization, or NATO, is a political-military alliance made up of 28 member countries, including the United States. Formed in 1949, NATO has played a unique and essential role in maintaining security and stability throughout the past six decades. It has grown and adapted to changing political environments and security challenges and, with enlargements, partnerships, and peacekeeping missions, has proven itself to be a continuingly effective Alliance.

The core principle on which NATO was founded is the Article V commitment, which states that an attack on one member is an attack on all. The first and only time this was put into action was after the September 11 terrorist attacks when NATO stood with the United States and helped secure American airspace. In 2003, NATO continued its commitment to combat terrorism by taking over command of the International Security Assistance Force (ISAF) mission in Afghanistan. Every one of NATO’s 28 members contributes to that mission, as do 22 non-NATO contributors. In Libya last year, NATO successfully intervened to protect civilians under attack by enforcing an arms embargo, maintaining a no-fly zone, and conducting air strikes against military targets. Other efforts include three peacekeeping missions to the Balkans, countering piracy off the Horn of Africa, and assisting relief efforts following an earthquake in Pakistan.

Read more on the NATO web site. You can also visit the web site for the United States Mission to NATO for much more information on the United States' relationship with the trans-Atlantic alliance.

View information on the countries comprising NATO or its partners, or learn more about the accomplishments of past NATO summits.