Nation: How the U.S. Got the Word

Unknown to the world outside, Warsaw Pact troops were pouring across Czechoslovakia's borders. In his White House basement office, Walt Rostow was routinely examining the backlog of paper that accumulates each evening on the desk of the President's special assistant for national security. The first hint of crisis came at 7:05 p.m., when Soviet Ambassador Anatoly Dobrynin told Rostow by telephone: "I have a message from Moscow which I am translating. I have been instructed to give it orally to the President."

In Russian-American intercourse, this ranks just below the hot line in urgency. Rostow arranged an 8 p.m. appointment with Lyndon...