One afternoon last week, just a few hours before the opening of the world security conference in San Francisco, President Harry Truman grabbed his mouse-colored fedora, rushed out of the White House to a waiting limousine. An aide called airily to newsmen: "We're going to the Pentagon, if you want to come along." Three reporters, representing the press associations, followed.
But at the Pentagon, the newsmen found they could not follow the President so easily. He was whisked immediately to the super-secret second-floor communications room, which has direct radio-telephone connections to London, SHAEF,...