At the end of World War II, the Soviet Union was still, technically speaking, an ally of the United States, Great Britain, and France. Yet in the division of Germany and the City of Berlin into four zones of occupation, it became clear the Soviet Union wanted to control all of Germany and would be threatening to the Allies. Largely, the Soviet Union rested on posturing and bluffing, at least until the Allies introduced a new currency, the Deutschmark, which stabilized the West German economy. The Soviet response was a complete blockade of all rail and barge traffic into Berlin. This made the supplies in West Berlin limited, and the only way in was through air deliveries. Remarkably, the Allies not only began the Berlin airlift, but they turned it into a massive success. Needing to deliver 6,000 tons of goods each day, after two months the Berlin airlift was surpassing that number regularly. By the following Spring, the airlift had survived a tough winter and set new records for deliveries. In the face of such an effort, the Soviet Union decided to back off of its blockade.