1 The blockade of Berlin was the result of a situation which developed mainly as a consequence of decisions made during the war. It was the climax of one phase of a planned and deliberate attempt by the Russians to force the Western allies out of Berlin.
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4 The Potsdam Agreement consisted of a comparatively short statement of principle and was not a statute book for the government of Germany. Consequently, co-operation and good faith on the part of the allies was required in co-ordinated and effective government of Berlin was to be obtained. Unfortunately, the Russian attitude prevented this.
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5 Owing to this lack of collaboration, the four power control of Berlin was bound to fail and gradually the administration of the Eastern and Western sectors of the city grew farther apart until the sectors became virtually two separate cities with separate city governments and separate police forces. The split between the two sectors was made complete by the Allied currency reform which was introduced in June 1948. This was caused by the Soviets refusal to co-operate and resulted in each sector having a different currency.