Cold War

The period after World War II was awkward even for the Allies. Events in World War II led to tensions between the Soviet Union and the other Allies. The main reason for this was that the Allies did not help the USSR fight against Hitler and open another front to help the the Soviet Union.

At the Yalta conference Stalin agreed to allow free elections in Eastern Europe, of course he did not keep his promise and instead took control of most of the governments in Eastern Europe.

Yalta

Tito, the dictatorial leader of Yugoslavia, did resist Soviet power to an extent. Despite abiding by many of their rules, he occasionally sought independent policies. He made Yugoslavia the most liberal of the Communist countries, but that is not saying much.

The first major "conflict" of the Cold War was the division and governance of Germany. After WWII, the Allies: the UK, US, France and the USSR, occupied four different zones of Germany. 

The Allies began to realize that Stalin would not obey his promise of letting the other Eastern European countries rule on their own. This was seen in the Communist takeover of Czechoslovakia and Poland in the mid 1940s. Winston Churchill described it as if "an iron curtain had descended across Europe".

After WWII, the Marshall Plan helped provide vital aid for Western European countries (and Yugoslavia) to help them recover in 1948.

The antagonism between powers grew and came to a head in Berlin. Berlin was in an awkward position quite literally. It was firmly in Eastern Germany (what would become the German Democratic Republic), but there was a Western portion of the city. The Soviet Union did not like this and so they blockaded the city in 1948.

In response to this the Allies formed the famous Berlin Airlift which provided supplies and food to the citizens of West Berlin until the Soviet Union lifted their blockade in 1949.

The Soviet Union kept trying to test the boundaries that had been set out for it. Earlier the Truman Doctrine said that the US would help any country resist Communism and had helped Greece and Turkey.

President Eisenhower of the US described how different countries might fall like "dominoes" in his Domino Theory. The US wished to contain Soviet influence, but the USSR thought otherwise. The North Atlantic Treaty (NATO) was formed in 1949 with the US, Canada, Britain and other European countries to provide collective security. In response to this the USSR formed the Warsaw Pact with the Eastern European countries in 1954.

The issue of the Aswan dam also showed Cold War tensions and had the USA and Britain withdrawing their help when Nasser, president of Egypt, also asked the USSR for money.

In 1961 the Berlin Wall was constructed to prevent Eastern German citizens from escaping.

Meanwhile things got very hot in the Cold War with the Cuban missile crisis. President Kennedy and Khrushchev reached an agreement and the Soviets agreed to not put nuclear missiles in Cuba. This showed the extent to which the arms race and the construction of the atomic and later hydrogen bombs had changed foreign relations between nuclear powers.

The Soviet Union also had to deal with many revolutions against their rule in Eastern Europe. One of these included Imre Nagy, a Hungarian who revolted against Soviet rule. The revolt was crushed with Soviet and Warsaw pact troops in 1956. Later on in 1968 the Prague Spring, a revolt led by Alexander Dubcek against Soviet government was crushed again by Soviet and Warsaw troops.

Finally, the revolution that arguably broke the USSR was the Solidarity movement in Poland. Led by Lech Walesa, the Solidarnosc challenged Soviet power. Along with support from Pope John Paul II and Reagan, the USSR began to show signs of weakness. 

The new leader of the USSR, Gorbachev (the previous leader was Brezhnev) brought about two new policies of glasnot (openness) and perestroika (reform) to the USSR. 

Soon large amounts of demonstrations and revolts in Eastern bloc countries forced the Soviets from power. Walesa was made president of Poland, and in Czechoslovakia the Velvet Revolution put Vaclav Havel and Alexander Dubcek in power through a bloodless takeover.

The Berlin Wall was finally torn down in in 1989 after Honecker was forced to resign in East Germany.

  Other  revolutions occurred in countries. By 1990s the Soviet Union had collapsed.