At the end of the forties, the tension between the two main powers, USA and USSR, reached very high levels. It was the start of the so-called "Cold War."

The most acute phase of the cold war was determined by two important events occurred in 1949: firstly, the burst of the Soviet atomic bomb, which took away from USA the monopoly in this vital field; secondly, the proclamation of the Popular Chinese Republic, which added that huge Country to the communist side.

Both of the events seemed, in a different way, to modify the relationships between the communist world and the capitalistic one. As soon as the fragile balance broke, an armed conflict became inevitable. The spark was the difficult situation of Korea. The USA reacted to support South Korea, ruled by a pro-Western regime, against the invasion led by the communist North Korea, politically and militarily supported by...