At the end of World War II, the French economy suffered from low production and an excess of money, which led to rapid inflation. The Vichy experiments at planning and the postwar nationalization of key industries—coal, gas, electricity, and some banks and insurance companies—prepared the way for bold efforts to energize the economy. Beginning in 1946, Jean Monnet, head of the state planning commission, administered a program to break through traditional economic bottlenecks by stimulating investment and thereby production. Part of the investment capital was provided by the United States under the Marshall Plan.

In addition, France and other European nations recognized how economic isolationism had undermined all their economies during the 1930s. They began to form international associations to promote more broadly based economic growth and to lay the basis for possible long-term political integration. An additional incentive to form such associations was the fear that an economically weak and politically divided western Europe would invite further expansion by the Soviet Union, which after World War II had established a broad band of satellite countries in eastern and central Europe.