North Atlantic Treaty Organization (NATO)

 NATO is an intergovernmental military alliance between several North American and European states.

 The organization constitutes a system of collective defence whereby its member states agree to mutual defence in response to an attack by any external party.

 NATO's headquarters are located in Haren, Brussels, Belgium, while the headquarters of Allied Command Operations is near Mons.

 NATO is an Alliance that consists of 28 independent member countries across North America and Europe, the newest of which, Albania and Croatia.