Answer:
After the end of World War II, the world was divided into two clearly differentiated geopolitical poles: the democratic world, led by America, and the communist world, led by the Soviet Union.
In this context, the main American concern was Europe, while the continent was devastated after the war, and the economies of these nations were going through a calamitous moment, which in turn made the appearance of communist revolutionary movements in the region more feasible.
In Greece, between 1946 and 1949, the first situation of this type occurred, where a series of communist ideology guerrillas tried to overthrow the Kingdom of Greece, seeking to establish a government aligned with the Soviets. Therefore, America decided to intervene supporting the Kingdom economically and with military resources, which ended up being decisive for the victory of this side against the communists.
