Nato: an attack on one is an attack on us all
On April 4, 1949, the growing Soviet threat in Europe led 12 western nations to form Nato.
In 1945, when Europe began the process of rebuilding after a shattering war, Russia chose not to withdraw from the central and eastern European countries it had overrun on its march to Berlin. Instead, it incorporated them into the USSR's sphere of influence, behind the "Iron Curtain" of communism that divided the continent from Murmansk in the north to the Turkish border in the south. Before long, any meaningful relations between western and eastern Europe effectively ceased.
To guard against further Soviet expansionism, in 1948 the United Kingdom, France, and the Low Countries signed the Brussels Treaty. It created "the Western European Union" to act as a military defensive bloc. However, it soon became apparent that a larger military collective defence entity was required if it was to be effective against the heavy build-up of Soviet troops behind the Iron Curtain.
The answer was Nato, and its founding document, the North Atlantic Treaty, was signed by 12 countries on April 4, 1949.
At Nato's heart is Article 5, which provides that any attack on a Nato member in Europe or North America is considered an attack on all members, who will come to the aid of the attacked member.
Six years later, when West Germany joined Nato in 1955, the USSR responded by forming the Warsaw Pact, uniting the Soviet Union, Albania, Bulgaria, Czechoslovakia, East Germany, Hungary, Poland and Romania in a "treaty of friendship, co-operation, and mutual assistance". The two sides of the Cold War were now firmly in place.
In July 1966, General Charles de Gaulle's policy of French military independence led to France pulling out of Nato's military command structure. Nato's headquarters was promptly relocated from Paris to Brussels. After 40 years, France formally rejoined Nato's command structure in 2009, but the organisation's headquarters remain in Belgium.
On the collapse of the USSR in 1992, the Warsaw Pact disbanded and Nato's role shifted.
Its priorities moved to dialogue and co-operation with former Warsaw Pact members and managing conflicts on the periphery of Europe.
Nato now has 28 members. Its founders were Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom and the United States. They were joined by: Greece and Turkey (1952); West Germany (1955); Spain (1982); the Czech Republic, Hungary, and Poland (1999); Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia (2004); and Albania and Croatia (2009).
Nato undertook no combat actions during the Cold War, relying instead on large-scale nuclear deterrence.
Since the fall of the Soviet Union, Nato has undertaken military operations in Bosnia-Herzegovina (1993), Kosovo (1999), Afghanistan (2003) and Libya (2011).
It has also undertaken training in Iraq (2004) and anti-piracy patrols in the Gulf of Aden (2009). Article 5 has been invoked only once, in 2001, following the death of around 3,000 people in the United States on 9/11 which led to Operation Eagle Assist and Operation Active Endeavour. (© The Daily Telegraph, London)