PARIS -- He sits in the cafe near the Luxembourg Gardens nursing a sugary orangeade, this man who caused metaphoric wisps of smoke to rise from Mikhail Gorbachev's ears two years ago. Then the KGB regularly and brutally visited him, taking his papers, his computer and, in petty cruelty, even his pipe. Now he travels to the West to interest foreign investors in his expanding magazine and newspaper business.

Meet Sergei Grigoryants, founder of Glasnost magazine, Gulag veteran and incurable dissident. His unfettered, capital-seeking presence here in Paris on a sunny day suggests a political story with a happy ending, one that illuminates the vast distance the Soviet Union has traveled on human rights since May 18, 1988, the last time I thought seriously about Grigoryants.

Right, Sergei? "Nyet!" Sergei responds, liquid brown eyes flashing with the resentment and distrust that come from a lifetime of oppression. Things have improved, he concedes under my prodding. But Westerners who mistake Mikhail Gorbachev, Boris Yeltsin and the rest of the perestroika crowd as democrats-in-waiting are being naive. Pulling the strings behind the perestroikrats are the cops of the KGB and the reactionary generals of the army.

Yipes, I think, as Grigoryants starts a long monologue on how the KGB put Gorbachev forward to attract Western sympathy and plans to discard him for Yeltsin when a crackdown at home is needed. Did a small group of us do verbal battle with Gorbachev in that conversation in Moscow two years ago on behalf of a man who can't take yes for an answer?

That was The Post interview in which Gorbachev denounced Grigoryants as a parasite and ''an alien phenomenon in our society, sponging on the positive aspects of perestroika.'' The Soviet leader made clear his disappointment that we would ask him about the imprisoning of a marginal character for a few days and the sacking of his office. We made clear our disappointment with the general secretary's answer.

But that was then. The jailings, daily harassment and travel bans that were every Soviet dissident's lot have eased significantly since. Moscow is still not paradise, Richard Schifter, the State Department's top expert on human rights, told Congress a few days ago, but it is ''a different world'' compared with the one that existed before Gorbachev. ''First Amendment freedoms have come to the Soviet Union's urban areas.''

As I read Schifter's remarks to him, Grigoryants vigorously shakes his head. ''Schifter is a polite man. Journalists do have more protection now against overt repression. But look at the violence that is happening, a lot of it against people who speak out or write the truth. I begin to think of the {government-sponsored} death squads in Latin America.''

At one level, Grigoryants is living, walking, talking proof of the adage that the oppressed take on the characteristics of their oppressors. Grigoryants seems as conspiracy-minded as the KGB men who put him in a prison camp for nine of his 49 years to punish him for his political views. He leaves the impression that if the Kremlin were leveled by an earthquake tomorrow, he would see it as another Gorbachev trick to gain sympathy.

I think few of us can at this point take aboard the idea that Gorbachev has given up Eastern Europe, wrecked the Soviet economy and shattered the Communist Party apparat as part of a far-seeing plot. I sift my memory for a comparison that Grigoryants' inconvenient words stir. Finally it comes:

He resembles a Washington journalist who disrupted State Department briefings in the Carter years by demanding that the department spokesman address the massacre of Polish officers by Soviet troops in the Katyn forest in 1940, an issue on which the spokesman had nothing new to say. Here was another man interested more by the question than any answer he might receive, intent on wreaking embarrassment rather than shedding light.

Or so it seemed. Now of course we know more about Katyn, because a new Polish government kept asking that same question and Gorbachev finally felt compelled to answer. The question turned from being an inconvenience to becoming the key to unraveling responsibility for a horror.

Will Grigoryants' ''obsession'' with the KGB turn out to be closer to reality than the more optimistic reporting of the press corps and embassies in Moscow? Only visionaries or confidence men will confidently predict an answer to that question, and it is impossible to tell one from the other in current circumstances.

But it is clear that this inconvenient Grigoryants has earned the right to keep raising his inconvenient questions about perestroika's ultimate aims. He has paid his dues and continues to challenge a system that is far from free. He is the only Moscow editor who has established a daily newspaper completely outside government control. His readership is tiny: his Glasnost magazine, printed in Russian in Moscow and Paris, sells only 30,000 copies a week.

This enables Gorbachev to scoff at him. But liberty needs the cranks who will not give up a cause simply because it is won. They help keep the world honest.