By the mid 1940's, the United States and Soviet Union were in a feud. This feud led to the Cold War which didn't really consist of official battles, but more of disagreements and uncompromisable disputes. The largest dispute was about communism and capitalism. At this point, the Soviet Union, eastern Europe, some countries in Asia, and Cuba were all Communist countries and each of them believe strongly that communism was better than capitalism. However, countries like the US, Canada, Southern Asia, and Eastern Europe believed strongly in capitalism. "The Sources of Soviet Conduct by X states "In these circumstances it is clear that the main element of any US policy toward the Soviet Union must be that of a long term, patient but vigilant containment of Russian expansive tendencies". X turned out to be George Kennan, an American Foreign Service officer stationed in Moscow. These beliefs led to no compromise, which then led to containment; the idea that the Soviet Union and Soviet communism should not be allowed to spread.
A smaller, yet serious conflict had then risen in Germany. At the end of World War II, Germany was split into 4 zones controlled by the British in the northwest, French in the west, America in the south, and Soviet Union in the east. The French, British, and American zones were all capitalistic regions, whereas the Soviet zone was communistic. Soon after, Berlin and the rest of Germany were split into East and West, separated by the Berlin wall. Due to the conflicts that had risen, Stalin decided to blockade any shipments coming into West Berlin. Now West Berlin was completely surrounded by communism and may have had to surrender if it weren't for the US and its allies. America supplied 2 million people by dropping supplies from spaces. Finally on may 12, 1949, Stalin removed the blockade.
Another area of containment was taking place in the Koreas. North Korea supported communism, however, South Korea supported capitalism.