The Marshall Plan was not the first great success of George F. Kennan's idea of containment. Kennan's idea of containment was first put into practice with the Truman Doctrine in 1947, which provided military aid to Greece and Turkey to prevent them from falling under Soviet control. The Marshall Plan, on the other hand, was a major economic recovery program that was launched in 1948 to help rebuild Europe after World War II. While the Marshall Plan was a great success in helping to restore Europe's economy, it was not the first major success of Kennan's idea of containment.