What Is It?:
The North Atlantic Treaty Organization (NATO) is often described as the largest and most successful military alliance the world has ever seen. The United States, Canada, Turkey, Greece, and most of Western Europe are members. More recently, a number of eastern European countries have joined bringing total membership to 26. Many more countries hope to join. The defining feature of NATO is its common security arrangement. This means all members pledge to treat an attack on one of them as an attack on all of them, a pledge referred to as the "Article 5" agreement.
Creation:
NATO was created with the signing of the North Atlantic Treaty on April 4, 1949. More than anything, the alliance was seen as a way to curb the expansion of the Soviet Union. By 1955, the Warsaw Pact, an alliance of Soviet-dominated states, was formed. Competition between the two alliances was the defining theme of the Cold War.
History:
NATO provided a strong framework for western military cooperation throughout the Cold War. Yet when the Cold War ended and the Warsaw Pact dissolved in 1991, NATO's war-fighting capability had never been used. And the "Article 5" pledge had never been called into action. Then in 1994, NATO took military action to end fighting in Bosnia and again in 1999 in Kosovo. The day after the September 11, 2001 attacks on the United States, NATO unanimously voted to invoke the "Article 5" provisions, and NATO now runs allied military operations in Afghanistan.
Leadership:
NATO's military operations are headed by the Supreme Allied Commander Europe. This position, first held by Dwight D. Eisenhower, has always been filled by an American. The commander answers to the North Atlantic Council, a gathering of ambassadors from all member countries. The council is led by the Secretary-General of NATO.
Location:
NATO headquarters are in Brussels, Belgium. The military operations command is based in Casteau, Belgium. The Allied Transformation Command, dealing with planning and training, is based in Norfolk, Virginia. Technically, all military assets of member states could be called upon by NATO if needed. This gives the NATO alliance a global reach with thousands of bases (as well as ships and aircraft) around the world.
Fun Fact:
NATO actually has a handful of aircraft bearing the NATO label. These are mostly cargo planes and AWACS (airborne radar for air traffic control). NATO AWACS planes patrolled the skies over the northeastern United States following the September 11, 2001 attacks.