It was the first small step toward European economic integration.

That act might not have been possible without the timely and inadvertent assistance of Joseph Stalin. It was the Soviet leader's ambition for conquest that persuaded the U.S. Congress to spend whatever was deemed necessary to stop him. And it was fear of Stalin that drove Europeans together for self-protection.

The U.S. was a reluctant superpower. Even as American dollars poured out, Washington made no pledge to defend Europe. Where the Red Army had stopped, sprawled across Eastern and Central Europe, Soviet power reigned and probed westward. Only when a communist insurgency threatened to overthrow the British-backed monarchy in Greece and when Soviet pressure grew on Turkey did the U.S. finally react. On March 12, 1947, Harry Truman announced a program of economic and military aid to both countries. In what became known as the Truman Doctrine, the President said it was henceforth U.S. policy "to support free peoples who are resisting attempted subjugation."

The Berlin crisis institutionalized the cold war. On July 6, 1948, the U.S. entered into discussions with its major allies to establish a military alliance, and on April 4, 1949, the North Atlantic Treaty was signed by 12 countries. West Germany joined in 1955. No one expected an immediate Soviet attack, nor were the U.S. and its war-weary European partners ready to invest in a military buildup. NATO essentially amounted to the U.S.'s throwing its nuclear cloak over Western Europe.

Fifty years later, it seems astonishing that the architecture of Europe's postwar order was established in so short a time.
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