NATO.North Atlantic Treaty Organization

The North Atlantic Treaty Organization or NATO. also called the

(North) Atlantic Alliance, is an intergovernmental military alliance

based on the North Atlantic Treaty which was signed on 4 April

1949. The organization constitutes a system of collective

defence whereby its member states agree to mutual defense in

response to an attack by any external party. NATO's

headquarters are in Brussels, Belgium, one of the 28 member

states across North America and Europe, the newest of which,

Albania and Croatia, joined in April 2009. An additional 22

countries participate in NATO's Partnership for Peace, with 15

other countries involved in institutionalized dialogue programs.

The combined military spending of all NATO members

constitutes over 70% of the world's defence spending.
For its first few years, NATO was not much more than a political

association. However, the Korean War galvanized the member

states, and an integrated military structure was built up under the

direction of two U.S. supreme commanders. The course of the

Cold War led to a rivalry with nations of the Warsaw Pact, which

formed in 1955. The first NATO Secretary General, Lord Ismay,

stated in 1949 that the organization's goal was "to keep the

Russians out, the Americans in, and the Germans down. Doubts

over the strength of the relationship between the European

states and the United States ebbed and flowed, along with

doubts over the credibility of the NATO defence against a

prospective Soviet invasion—doubts that led to the

development of the independent French nuclear deterrent and

the withdrawal of the French from NATO's military structure in

1966.
After the fall of the Berlin Wall in 1989, the organization became

drawn into the Breakup of Yugoslavia, and conducted their first

military interventions in Bosnia from 1991 to 1995 and later

Yugoslavia in 1999. Politically, the organization sought better

relations with former Cold War rivals, which culminated with

several former Warsaw Pact states joining the alliance in 1999

and 2004. The September 2001 attacks signalled the only

occasion in NATO's history that Article 5 of the North Atlantic

treaty has been invoked as an attack on all NATO

members.After the attack, troops were deployed to Afghanistan

under the NATO-led ISAF, and the organization continues to

operate in a range of roles, including sending trainers to Iraq,

assisting in counter-piracy operations and most recently in 2011

enforcing a no-fly zone over Libya in accordance with UN

Security Council Resolution 1973.