The Grand Alliance was created in 1941. It was a partnership between Britain, the USA and the Soviet Union.
The Tehran Conference: 1943
They agreed to set up an organisation, which would later become NATO
The Soviet Union would have more of Poland
The Soviet Union would declare war on Japan after Germany was defeated
Stalin was happy after the Tehran conference but Churchill was not.
The Yalta Conference: February 1945
Germany would be split into 4 areas, with each belonging to Britain, the USA, the Soviet Union and France
Germany would be demilitarised
Countries which were previously under Nazi rule would have democratic elections
The UN (United Nations) would be set up
Poland would become part of the Soviet sphere of influence
The Potsdam Conference: July-August 1945
The Nazi Party was banned and war criminals would be prosecuted
As well as Germany, Berlin would be split into 4 zones
After Germany surrendered, the Grand Alliance began to fall apart, as Truman, the new US presidnet, was much more wary of the Soviet Union than Roosevelt was. This increased tension between the Allies.
Stalin wanted Germany to pay large amounts in reparations.
The Long Telegram: 1946
A report from US ambassador Kennan in Moscow to Truman
It said that the Soviet Union saw capitalism as a threat to communism
That the Soviet Union was building its military power
That peace between a communist USSR and a capitalist USA was not possible
Novikov's Telegram: 1946
A report from Novikov, the Soviet ambassador in the USA
It said that the USA wanted world domination and was building its military strength
That the USA was preparing its people for war with the Soviet Union
Bulgaria:
A communist government was elected in 1945, and all elected non-communists were executed
Romania:
A communist-led coalition took power
By 1947, the communists had taken over and Romania became a one-party state
Poland:
At Yalta, Stalin promised to set up a joint communist/non-communist government
He then invited 16 non-communist leader to Moscow and arrested them
The communists then 'won' the election
Hungary:
The communists lost the 1945 election, but the communist leader Rakosi took control of the secret police
This led to him imprisoning and executing his opponents
Hungary then became a communist state
Czechoslovakia:
Edward Benes set up a coalition government
Communists still retained control of the army, the radio and the secret police
In 1948, they seized power completely, and turned the country into a communist state
East Germany:
The original Soviet-occupied zone in Germany became a communist state in October 1949
The USA saw Stalins expansion into Eastern Europe as him breaking the agreements made at Yalta.
Others saw it as a stepping-stone for the Soviet Union to take over Western Europe.
The Soviet Union argued that it needed its satellite states as a buffer zone to protect itself from the West.