"MADRID" IS shorthand for the East-West conference on human rights and European security and cooperation. It's been going on so long and, it seems, so inconclusively that most people tuned out a year or two ago. It's a good time to tune back in. The conference may or may not soon produce some final deeds and words of value; that's up to Moscow. But that's also just the point: for its part, the United States has done its job and produced a sustained demonstration of allied political cooperation. Given the strains otherwise evident in Atlantic relations, that is no trivial result.

"Madrid" followed "Helsinki," the mid-1970s conference representing a joint Soviet-American effort to spread the benefits of d,etente in Europe. The inherent difficulties of this project, plus the external shocks that shriveled Soviet-American d,etente as the 1970s went on, took their toll from the moment the Madrid meeting opened in 1980. Nonetheless, Mr. Reagan, surprising some skeptics, has kept in mind that the main purpose is not simply to make propaganda but to improve conditions for people, and that for this purpose the maintenance of allied unity is essential. He has had support from Max Kampelman, President Carter's man at Madrid, whom he kept on.

Madrid is a battle for inches, with the West on the attack mainly on human rights and the East attempting to set up a defense on the line of "peace." There is no way to compel Moscow to make good, say, on free emigration or on fair treatment of individuals who try to monitor its earlier human rights pledges, but there is a way to make it pay a price in Western opinion. If the Soviet bloc is not really a freer place than it was when the so-called Helsinki process began, then for all the frustration it causes, continuation of the process at least lets the West keep faith with those in the East it seeks to aid.

Why does Moscow stay in a forum where its rights record is perennially at center stage? For one thing, because setting up such a forum was the price it was willing to pay for formal Western acceptance of the national borders the Red Army drew in Eastern Europe after World War II. For another, because the Kremlin wants to pull West Europeans into a new forum to discuss disarmament and other "peace" issues. Even here, however, the West has hung pretty tough.

In its first phase, the forum under discussion would take up measures to reduce the chance of surprise attack in Europe--advance notice of maneuvers, inspection of troop movements. It would have its uses for Soviet diplomacy. Still, "surprise attack" can only mean Soviet surprise attack. That agenda builds in a continuing multilateral focus on a matter of great concern in the West.

Things have gone poorly in Soviet-American affairs in recent years, especially in Mr. Reagan's time. Many in the West have feared he was pushing his tactic of hard bargaining to a point of no return both with Moscow and with Europe. At Madrid, nonetheless, there are grounds for thinking an agreement with Moscow is in sight. It would be a Reagan first. It would also be an Andropov first. Watch Madrid.