France, April 4 -- Seventy five years after it was founded on 4 April 1949, in the wake of World War II, the North Atlantic Treaty Organisation - better known as NATO - is bigger than ever, but allies worry that a rising current of isolationism in American politics could lead to a drop in financial support from the defence alliance's leader.

NATO was born in 1949 out of growing concern over increasing Soviet control over Eastern Europe.

Against the backdrop of a communist coup in Czechoslovakia and Moscow's blockade against West Berlin, 12 countries in Western Europe and North America - wartime allies the United States, Canada, the United Kingdom, Belgium, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway and Portugal...