BARRING an unforeseen reversal, the symbolic toppling of the Berlin Wall last Thursday will go down as one of the 20th century's great events. Free travel between East and West Berlin is Stalinism's white flag of surrender to the idea of capitalist democracy - and history may record it as an Armistice Day, a V-E Day of the cold war. The Berlin drama, optimistically viewed, signals a new Europe, a different economic framework, and new roles for NATO and the Warsaw pact.
The Berlin Wall's tense history is vivid to those who lived through the 1950s and '60s: black-and-white newsreel images of giant turboprop airplanes lumbering over the city, of ``The Spy Who Came in From the Cold,'' of President Kennedy's ``Ich bin ein Berliner'' speech.
The Wall, its cement blocks topped with barbed wire and anxious searchlights, appeared intractable. Since 1961, scores have died in their efforts to cross it. Now ordinary East Berliners - those who have had no political voice - have suddenly taken history into their own hands, and the East German leaders can do nothing about it.
The wall is effectively down. Soviet spokesman Gennadi Gerimasov says that East Germany can experiment with free elections so long as it agrees not to withdraw from the Warsaw Pact.
Despite the jubilation, the prospects of social and economic instability cannot be ignored. As the geopolitics of Europe shift, all parties need to exercise self-restraint and sobriety - the Soviets, the East and West Germans, and NATO countries, including the United States.
This is a grass-roots revolution with its own momentum. It is not a time for overly assured statements about German reunification from West German Chancellor Helmut Kohl - even though reunification may well be an eventual outcome. There are signs that Mikhail Gorbachev's own domestic problems may force him to try to slow the rate of change in the East bloc in the coming year. This could be the key issue in the upcoming shipboard summit - Gorbachev might need President Bush to endorse measured change. Mr. Bush will be sympathetic. But he also needs to know that free elections will take place in East bloc nations that want them - and that the 400,000 Soviet troops in the East Germany will be slowly pulled out.
In the coming years a strong, demilitarized NATO can help shape a new Europe. Mr. Bush should concentrate on keeping NATO alliances strong and vital.
The hot spot now, in the most basic human sense, is in Berlin. Tens of thousands are flocking there. Ethnic tensions among the Turkish population and the 30,000 displaced Poles may increase. Housing, traffic, jobs - all need to be dealt with.
Those in the newly legalized New Forum opposition group in East Germany ask that their countrymen think twice about leaving. The demand to shape a more democratic system there, with increasing economic ties to the West, has been unleashed.