As 11 foreign ministers, Secretary of State Dean Acheson and President Truman gathered for the treaty signing, a Marine band played Gershwin tunes, including "I Got Plenty of Nothin'" and "It Ain't Necessarily So" from Porgy and Bess.
That helped ease the tension in the air.
Stalin's blockade of Berlin was met by a massive American airlift, and some wondered about what the Soviet dictator would try next.
The treaty, in effect, spread an American nuclear umbrella over nervous allies in Europe. NATO's first secretary-general, Britain's Lord Ismay, is said to have neatly summed up the purpose of the alliance to "keep the Russians out, the Americans in, and the Germans down."
In 1955, West Germany joined NATO and was encouraged to re-arm, but with the understanding that its troops would be under control of the NATO supreme commander.
The Soviets responded by creating the Warsaw Pact with their satellites in the years after Stalin's death in 1953. Tensions between NATO and the Warsaw Pact went up and down, along what Winston Churchill called "the Iron Curtain." Probably the most perilous moment came in 1961, when Soviet and American tanks faced each other almost muzzle-to-muzzle at Berlin's Checkpoint Charlie in an escalating dispute over Allied access rights.
I stood between the menacing-looking tanks and said into the CBS camera that this may be the way World War III starts. Finally, President Kennedy and Nikita Khrushchev agreed to withdraw the tanks.
In the end, the Warsaw Pact fell apart and the Soviet Union collapsed.
The original 12 NATO members were joined by former Soviet republics and satellites. A link was forged with Russia in the form of a NATO-Russia Council.
NATO, its original purpose gone, has been given missions in Serbia and Bosnia and now in Afghanistan, where the United States presses for more troops.
But today, as NATO celebrates its past glory, it has lost its sense of mission even as it has multiplied its membership. Today, the Russians look suspiciously on NATO encroachment, but this aging alliance poses no threat to anybody.