IT HAS DAWNED on the West since Pope John Paul II completed his visit to Poland that he and Gen. Wojciech Jaruzelski probably discussed arrangements for a future without Lech Walesa, whom the regime defines now strictly as a private citizen, and without Solidarity, the free trade union organization he led before it was crushed by martial law 18 months ago. The prospect has launched a wave of anxiety, mixed in some places with guilt and in others with rage. How can people of conscience in the West stand by and watch this brave and genuine democratic leader dealt out of the game?

The answer to that question is familiar, of course, to anyone who knows Poland. Soviet power overhangs Polish destiny and there are limits to what Poles on their own can do. Many here who long for a display of Polish defiance scarcely consider that the consequences would be visited on Poles alone. In this matter it is important to remember that the pope's credentials are beyond suspicion. He is Polish. He represents a church completely identified with the Polish nation. In his first return to Poland as pope, he generated the mass feeling that created Solidarity, and in his second he nourished the spirit that survived the organization's demise. Thereby he collected the power he used in his negotiations with the regime.

In the White House, interestingly, there is no visible longing for another Polish flameout. As the pope flew back to Rome, President Reagan noted the "restraint" Gen. Jaruzelski had shown during the visit and promised to reciprocate if the regime took specific steps to relax martial law. Such steps could conceivably start in the next few weeks, if the Soviets decide to support the pattern of wary coexistence explored by the general and the pope--a pattern more liberal than anything dreamed of elsewhere in the Soviet bloc.

There is more than a trace of irony here, and it troubles some parts of Mr. Reagan's core constituency. The administration came to power committed to an ideology supporting the virtual liberation of Eastern Europe from communist rule. It now finds itself conducting the familiar American postwar policy of attempting at the margin to encourage East European nations that are interested to extend their field of national maneuver. It is a limited policy, but a realistic and mature one that is shared by the American allies.