NATO, also called the Atlantic Alliance or North Atlantic Pact, was signed on 4th of April 1949 as a response to the Berlin blockade in 1948. A unified High Command of the allied forces was put in place in 1950. At the beginning 12 countries were signatories; the USA and Canada and 10 European countries: Belgium, Denmark, France, Great Britain, Iceland, Italy, Luxemburg, Norway, the Netherlands and Portugal. Turkey and Greece followed in 1952 and the Federal Republic of Germany in 1955. The latter’s membership provoked the birth of the Warsaw Pact, on 14th May 1955. France left the unified command in 1966 (but remains a member of the Alliance), which led Belgium since then to house the Organisation’s headquarters (Brussels) and the military command (SHAPE at Casteau, close to Mons). France rejoined the unified command in 2009. Today NATO numbers 28 members and has expanded to the East following the fall of the Berlin Wall in 1989. The first of the Eastern bloc’s nations to join, on 3rd October 1990, was the ex-East Germany, when it reunified with the Federal Republic of Germany. NATO has been the heart of the defence policy of countries who opposed the expansion of communist regimes. Since the implosion of The USSR in 1991, it has been confronted with new threats it has had had to respond to. It is thus that it intervened militarily when faced with the rise of nationalisms in Eastern Europe (Bosnia in 1994 and Kosovo in 1999) and international terrorism (Afghanistan today).