ONE OF THE LEADERS of the Polish union movement is a man named Adam Michnik. I saw him one night at a meeting of dissidents in Warsaw. He was already famous for helping to organize an underground university, for being a very brave teacher, and so when he came into the room there was some murmuring, a general stirring. They thought he was a hero. I thought he was doomed.

Maybe he still is, but the sense I had then, the sense that no man and no country on the border of the Soviet Union could do anything but adhere to its party line, has vanished. In its place has come an appreciation for the Polish Revolution, for all revolution and especially for the notion that there are times when events are the master of men and not the other way around.

We learned this lesson in Vietnam and the Soviets are learning it now in Poland and maybe also in Afghanistan. However things turn out in Poland, it is already clear that from the Soviet viewpoint they have already gone too far -- and there isn't much the Soviets can do about it. One government fell, a union called Solidarity has become a political force in a country where the Communist Party is supposed to be the only political force and the party itself has been forced to recognize it. These are new rules indeed.

Suddenly, the Soviet Union seems tentative -- something less than the totally evil and totally unrestrained enemy we have all been taught to hate and fear. This has happened despite the fact that the Soviet Union is not just close to Poland, but sits right on it. Its allies, some of them even more hardline than Mother Russia, sit on the other borders and Soviet troops are camped in the interior of Poland, garrisoned there under treaties of matual friendship. Still, there is little the Soviets seem able to do.

This is the case despite the fact that the Soviet Union is not constrained by either morality or American-style domestic considerations. It does not have a press that will be critical of the government for trying to influence events in another country. No congressional committee will hold hearings. There will be no teach-in at Moscow U. and no columnist will take potshots, yelling the equivalant of "Vietnam, Vietnam" -- maybe "Afghanistan, Afghanistan."

If the Soviets appreciate this lesson, it is not clear that we do. From what we are being told, it seems that all we have to do to control events in El Salvador is put in some muscle, withhold aid and then offer it, put some technicians on the ground and let everyone around know which guys are our guys. Having done this, we can then expect that things will start turning our way.

There is a similar myth about Iran: We lost it. We cold have affected or changed the outcome of that revolution, bucked up the shah, made him stand firm and then all those millions of people, motivated by forces we little understood, would have turned tail and gone back to the 19th century whence they came.

Much of this is a variation of the old who-los-China refrain which held the Democratic Party or the State Department or Communists therein responsible for the "loss" of a hugh country with a population of one billion and that wasn't ours in the first place. That China had its own agenda, that forces were under way that could not be controlled, was something that did not occur to some people.

The fact of the matter, is, though, that there really are such things as revolutions -- an unleashing of incredible force and power that historians would love to better understnad. It has happened time and time again in history, and this nation was born in one that fundamentally changed the world. Only a fool thinks they can be controlled simply -- if at all.

This is what is happening now in Poland. Maybe the Soviets will prevail, but if they do so it will be at enormous cost. Like any other nation, they, too, are sometimes the captive of events, dancing on the string that is history -- neither as invincible nor as all-powerful as we, or maybe they, would like to believe. The rules of history are not waived for them, either. This is Adam Michnik's latest lesson. We are all his students.