The strenuous period from mid 40s till the late 80s between the U.S and erstwhile Soviet Union is termed as the Cold War. It immediately began after the termination of World War II.
The term Cold War was coined because of the fact that there was no actual war in the form of battlefield, but there was the fear of use of nuclear weapons by either country. This war nevertheless included many secondary conflicts such as those experienced in Vietnam as well as Korea. The 1962 Cuban missile crisis needs a special mention because it nearly resulted in a nuclear war between the 2 countries.
American spy planes gauged the Russian intermediate ballistic missile through certain photographs. These ballistic missiles had the capacity of carrying nuclear payloads. A total of 64 missiles were sent to Cuba. Out of these 62 missiles, 42 were of medium range and 24 were intermediate range missiles. The Russians were finally forced to remove these missiles due to pressure from America. The US had said that it would invade Cuba if the missiles were not taken away at the earliest.
Another factor which created discord between these to nations was the China. In 1949, the Soviet Union and China surfaced as great partners. This partnership saw a gradual decline and America took the advantage of this downfall. In 1971, the U.S formed a strategic alliance with China in order to corner the Soviet Union. In 1980, the Russians attacked Afghanistan. The U.S cleverly financed Afghanistan and trained the guerillas to take up arms against the Russian troops. A huge shift of armaments and military equipment took place in Afghanistan. This led to a major set back for the Soviet Union.
The Americans always feared that the Soviets would spread their communal ideology across the globe and will take over the entire Eastern Europe and parts of Asia. These two factors lead to a kind of resentment within Americans. The Soviets, on the other hand, feared the American acquisition of atomic power. The Soviets suspected that the Americans would use Western Europe as a base to counter them.
At last, after the downfall and collapse of the Soviet Union in the year 1991 the Cold War was finally called off.