THE POLISH crisis has produced a new and painful showing of Atlantic disarray. The United States moved to condemn the coup in Warsaw and to impose limited sanctions against the Polish regime and the Kremlin. But the allies have variously hung back on both fronts.

Why? Poland is not remote from Europe or from Europe's interest or security. It is in the heart of the NATO treaty area. What is happening there is precisely the sort of intimidation and violence NATO was organized to protect its members against. West Europe's own neighbors are the perpetrators. Is West Europe satisfied to have Americans come to feel that the suppression of democratic movements by force on the European continent is of small consequence to Europeans?

The geopolitical facts of life being constant, the values at stake in Poland cannot be defended there in the same ways that they presumably would be defended if they were under siege in, say, Germany. The fact remains that what Solidarity has been doing since 1980 is essentially to assert Poland's European heritage. Morally, Europeans should be first to recognize this.

Helmut Schmidt's response is especially puzzling. The West German chancellor presumably does not lack sympathy for Solidarity. He surely understands the role the United States plays in helping to keep the European balance. But he has seemed distracted. The declaration of martial law caused no perceptible ripple in his talks with his East German counterpart. He ignores the damage martial law has done to his concept of d,etente with the East, or at least so one gathers from the comments he has made from the vacation beach in Florida.

Some people here ask why Mr. Reagan did not wait to bring the allies along on sanctions. The Europeans appear relieved that he did not put them on the spot. What might consultation have produced? Perhaps, in a month's time, an agreement to cut back the delivery of third-class mail?

A case can always be made for a grin-and-bear-it policy: it saves wear and tear, minimizes public embarrassment, and lets the Alliance limp on. But the purpose of the Alliance is to give Europe the benefits that flow from everyone's understanding that the United States cares. Is it in Europe's interest for the feeling to grow in the United States that Europe itself does not care?

Not so long ago Mr. Reagan was being widely depicted as something of a madman brandishing nuclear weapons and blowing on the East-West coals. He made a major impact on responsible Atlantic opinion by the way he moved to the table with the Soviet Union; those talks, on nuclear weapons in Europe, go on. Now in some European quarters it is suggested that he is overreacting to Poland for his own shadowy political or diplomatic reasons.

We don't think Mr. Reagan is overreacting: he continues, after all, to solve the Soviet Union's farm crisis for it. We think some Europeans are underreacting. Each time there is a crisis--Iran, Afghanistan, the Middle East, Poland--the Atlantic gap gets a bit wider. No one event is determinative but the cumulative effect is real.