SOME INTRIGUINGLY moderate 'signals" are being sent out by the Palestinians. Why? Having been slowed in lebanon, they are being urged by their Arab allies and patrons to get aboard the Geneva train: to frame their political goals in a way that will make possible the negotiations of a Mideast settlement including, for them, a West Bank-Gaza state. Since the political distance to be moved is as great as the diversity within their ranks, the signals are few and faint and, by an absolute standard, inadequate. Typically, a Palestinian offers a private hint of movement; once revealed, it is taken back. Or an Arab government makes a similar feint: President Sadat of Egypt recently suggested that a Palestinian state be linked to Jordan. This seeming reversal of the Arabs' 1974 Rabat decision to hand over the West Bank to the PLO was itself reversed, or blurred, a few days later. The common direction, if not the pace and ultimate destination, is nonetheless clear. The Arabs want to go to Geneva and, somehow, to carry the Palestinians along with them.

It makes a difference how others regard this process. The Israelis, not yet ready as a government or a people to countenance establishment of a Palestinian state next door, tend to regard each Palestinian move forward as a trick and each move backward as confirmation of a grim but familiar status quo. They resist and resent being asked to be hospitable to a movement that officially still calls for the elimination of Isarel as a state. This is entirely understandable. What is not so easy to accept is the Israeli refusal to show the degree of hospitality to Palestinian moderation that would give the modrates the help they need to turn the still predominantly radical Palestinian movement around. A refusal to pursue conciliation on one side feeds a similiar tendency on the other. The Israelis, like the Palestinians, need a broader view of their own self-interest.

The United States, however, has no similar political need to stand back from Palestinian or other Arab initiatives. On the contrary, it has a diplomatic need not to do so. There is no question of America's rushing to impose a settlement of its own design upon the Israelis, as the Arabs and their more impatient U.S. supporters would prefer. In return for the difficult compromises it will eventually have to make, Israel demands and deserves matching compromises - concrete steps of acceptance - from the Arabs. Yet the United States must show itself receptive to moderation whenever and wherever that quality, so rare in the region, shows its pleasing head. Moderate Palestinians, inside or outside the PLO, should know they have American understanding. King Hussein of Jordan has long been ready to play as sustantial a West Bank role as his fellow Arabs would permit him; the United States should do what it quietly can to gentle that process along.

It will be some months before the Carter administration can engage fully in the diplomacy of the Middle East. Mr. Carter can use those months to do more than study the problem. If things go well, he can also strengthen the domestic political base he will need to undergird the difficult measures, sure to be resisted at least initially by Arabs and Israelis alike, that effective diplomacy will require. Meanwhile, no opportunity to nourish the development of moderation, among Israelis as well as Arabs, should be lost.