AP Photo

Twenty years ago, late on a Thursday evening in Berlin, the cement and concertina-wire symbol of the Cold War was breached, inadvertently opened by a botched answer of a flustered East German Communist Party apparatchik.

Announcing a loosening in border-crossing policy, he was peppered with questions on when the change would take effect.

"Immediately," he said, shuffling his notes. "Without delay." "Also in Berlin?" presses a reporter. "Yes, yes," comes the response.

Reporters rush to file; word is broadcast over Western media stations on the channels no East German is allowed to watch, but everyone does. The streets fill as people head for the Wall.

The rest, as they say, is history: Bewildered East Germans step past the feared Grenztruppen border guards,...