How did the Cold War develop? 1943–56

The Teheran, Yalta and Potsdam Conferences

The attitudes of Stalin and Truman and the ideological differences between the superpowers.

The establishment and control of the Soviet satellite states

Cominform and Comecon.

The growing involvement of the USA in Europe

The Truman Doctrine

The Marshall Plan

Bizonia

The Berlin Blockade/Airlift

The formation of NATO.

Military developments and the beginnings of the arms race.

The impact of Soviet rule on Hungary

Rakosi

De-Stalinisation and optimism

The Hungarian Revolution: Nagy and his demands, Soviet reaction and uprising, the death of Nagy, the re-establishment of Soviet control and international
reaction.

The Cold War, 1956 - 1969.

The Berlin Crisis

The refugee problem
Khrushchev's challenge to the USA
Summit Conference and Eisenhower
Challenge to Kennedy
Construction of the Berlin Wall and its impact
Kennedy's visit to Berlin, 1963.

The Cuban Missile Crisis

How did the USA react to the Cuban Revolution?
Why did Khrushchev put missiles into Cuba?
Why did Kennedy react as he did?
Who won the Cuban Missile Crisis?

Berlin: Challenge to Kennedy

Source Material

Source: Aide memoire from Khruschev to Kennedy, June 1961

The peace treaty will specifically record the status of West Berlin as a free city, and the Soviet Union, like the other parties to the treaty, will, of course, strictly observe it and measures will also be taken to see to it that this status is also respected by the other countries. At the same time this will also mean the liquidation of the occupation régime in West Berlin with all the consequences arising from this. In particular, the questions of using land, water and air communications across the territory of the German Democratic Republic will have to be settled not otherwise than through appropriate agreements with the German Democratic Republic. This is only natural, since control over such communications is an inalienable right of any sovereign State.

Source: Kennedy Speech in response to the Aide Memoire sent by Khruschev

The real intent of the June 4 aide memoire is that East Berlin, a part of a city under 4-Power status, would be formally absorbed into the so-called German Democratic Republic while West Berlin, even though called a “free city,” would lose the protection presently provided by the Western Powers and become subject to the will of a totalitarian regime. Its leader, Herr Ulbricht, has made clear his intention, once this so-called “peace treaty” is signed, to curb West Berlin’s communications with the free world and to suffocate the freedom it now enjoys.

Source: Strategic Air Planning and Berlin

External link (pdf document). This is a copy of the now declassified documents that show that the US was preparing for a 'First Strike' option if the Berlin Crisis led to inevitable military conflict.