The comedy of errors that caused a wall to fall

History's judgment will probably call it a draw between rival claims to causality. Structural evolution in the Soviet bloc made the fall of the Berlin Wall possible. But a comedy of errors in East Berlin and Moscow on Nov. 9, 1989, ensured that the wall fell overnight.

The key words uttered by Communist party spokesman Günter Schabowski just before the main 7 p.m. news broadcasts were: "We decided today to make a regulation that will enable each citizen of the GDR [German Democratic Republic, or East Germany] to travel abroad over border crossings of the GDR."

A reporter asked when this plan would take effect. Mr. Schabowski, suddenly wondering whether, in the chaos, Moscow had ever been consulted about the measure, hesitated. Then, skimming a copy of the draft legislation that had been thrust into his hand minutes before the press conference began, he read out the word "immediately."

There was total confusion about precisely what it was that was supposed to happen "immediately." It had been expected that the leadership would ease travel abroad to try to stanch the flood of young East Germans who were escaping to the West every day via Hungary and Czechoslovakia, never to return. But it was clear that the party intended to maintain control by requiring official exit visas for travel – and by preserving the presence of Soviet forces in East Germany.

As soon as East Berliners heard the 7 p.m. news, at first a trickle and then a steadily growing horde set out for the wall's crossing points to West Berlin to test the ambiguity for themselves. By 10:30 p.m., the crush of East Berliners at the Bornholmer crossing was so great that the few hapless guards there – lacking any instructions from their superiors – faced the choice of letting the crowd through or shooting some at the front. They opted to lift the toll bar. Guards at all the other crossing points then followed suit.

Berliners from both sides partied all night on Kudamm Boulevard and on top of the wall. West Berliners showered flowers and bananas on the newcomers. And when eastern drivers of the ubiquitous no-frills Trabant cars, too, wedged their way through the openings, West Berliners greeted them by banging giddily on their hoods and roofs and invented the instant new verb of "trabitrommeln" – Trabi-drumming. Uncomprehending, grinning Berliners kept shouting ecstatically over and over, "Wahnsinn!" – this is pure madness!

Soviet diplomats in their giant embassy near the Brandenburg Gate were just as confused as everyone else and tried frantically to reach Moscow. They failed to rouse anyone because of the time difference.

It was not until Moscow bureaucrats woke up the next morning and saw the Berlin revelry on their own TV screens that they called back in some agitation. Their first question, according to Igor Maximychev, deputy Soviet ambassador, was: Did we approve of this?

The answer was no. And the rest is history.

• Elizabeth Pond, who covered Russia and Europe for the Monitor during the cold war, is the author of "Beyond the Wall: Germany's Road to Unification."