What is NATO?

  * April 4, 1949 - U.S., Canada and 10 West European states sign the Washington Treaty to create the North Atlantic Treaty Organization. Article 5 states: "The parties agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all..."
  * May 6, 1955 - West Germany joins NATO, prompting the Soviet Union eight days later to gather eight east European nations into the Warsaw Pact coalition.
  * March 10, 1966 - President Charles de Gaulle pulls France out of NATO's integrated military structure. NATO headquarters moves from Paris to Brussels the following year. France subsequently re-joins NATO's military command in 1993.
  * Dec 9-10, 1976 - NATO rejects Warsaw Pact proposals to renounce first use of nuclear arms and restrict membership.
  * Nov 19, 1990 - With the Cold War over, NATO and the Warsaw Pact issue a joint non-aggression declaration. Eight months later, the Warsaw Treaty Organization is officially disbanded.
  * Dec 16, 1995 - NATO launches largest military operation to date, in support of the Bosnian peace agreement.
  * March 24, 1999 - NATO begins air strikes against Yugoslavia over Kosovo, the first time it has used force against a sovereign state without U.N. approval.
  * Sept 12, 2001 - NATO invokes Article 5 for first time after the 9/11 attacks on United States, later deploying Airborne Warning and Control Systems aircraft to United States.
  * Aug 11, 2003 - NATO takes command of Kabul-based peacekeeping in Afghanistan, its first deployment outside Europe or North America, and one that will see its forces engage in their bloodiest ground combat.
  * April 2, 2004 - NATO expands to 26 members when former communist states Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia and Slovenia join, five years after the entry of Czech Republic, Hungary and Poland.
  * Dec 8, 2005 - NATO foreign ministers approve a plan to expand the alliance's...