For the United States, the signing of the Lebanese-Israeli troop-withdrawal agreement is a considerable diplomatic achievement. US Secretary of State George Shultz earns deserved credit for his skillful negotation. The question, however, is when the agreement will be carried out. That will depend on whether Mr. Shultz will be equally successful in persuading Syria and the Palestine Liberation Organization to agree to withdraw their forces - on which implementation of the Lebanese-Israeli pact is contingent. And that, in turn, will depend on whether the United States is able to establish its credibility with respect to a larger Middle East peace settlement.
For Israel, too, the agreement represents a major achievement. Israel did not get everything it wanted, but it presumably got enough to be assured of security along the Israeli-Lebanese border and thus be able to justify its invasion of Lebanon. Prime Minister Begin has in effect pulled off a diplomatic coup, improving his relations with Washington and enhancing Israel's image as a peacemaker following its invasion of Lebanon and the terrible onus it bore in the massacre of Palestinian refugees. And, as long as the Syrians do not accept the agreement, Israeli forces can remain in Lebanon indefinitely.
And the Arabs? Will they show courage and seize the moment to keep the diplomatic momentum going and move forward the peace process? Or, as has unfortunately happened in the past, will they weakly resist all diplomatic efforts to make progress and in the end lose still another opportunity to advance the Palestinian cause of self-determination? Washington no doubt is heartened by the fact that Egypt, Jordan, Saudi Arabia, and some others are coming to the support of the Israeli-Lebanese agreement. But can they prevail on the Syrians and the PLO? It is saddening to hear PLO leader Yasser Arafat saying - after he had made a trip to PLO units in Lebanon - that war is the only way to change the balance of power in the Middle East.
Mr. Arafat should know that he risks losing whatever support and sympathy from the American public the Palestinians have managed to win as a result of Israeli aggression in Lebanon and in the occupied West Bank. In order to recoup the PLO's military and political strength following its defeat in Lebanon, he seems to be choosing the side of the Syrians and the Russians.But is he calculating the impact in the United States of stepped-up Soviet involvement - or of the Israeli agreement to a troop pullback? He and other Arab leaders must surely see that, in the eyes of many Americans, Israel now looks to be the more responsible party. Especially after Mr. Arafat and the PLO also refused to let King Hussein of Jordan join peace talks on West Bank autonomy.
This is not to deny that Syria and the PLO have legitimate concerns of their own. The Syrians can logically ask, for instance, how their security needs will be met in Lebanon (their presence in the Bekaa Valley gives them some protection from Israel, which sits on the Golan Heights and is thus only 15 miles from Damascus). And what is in those ''secret understandings'' in the Israeli-Lebanese agreement? In its broad outlines, the accord seems to be a sensible compromise; but its provisions are not fully known.
No doubt the Syrians will also want to know what is in it for them if they do agree to withdraw their forces. So far the United States has not demonstrated equal diplomatic skill in resolving the larger Mideast problem - the problem of Israeli expansionism, including Israeli annexation of the Golan Heights and the continuing Israeli settlement of the West Bank. What, the Syrians may want to know, is US strategy after a Lebanese pullout? What guarantee have they that, once foreign forces are withdrawn from Lebanon, Israel will not simply continue its policy of colonization? Inasmuch as the US has not managed to influence fundamental Israeli policy, it can hardly be totally unsympathetic to these Arab hestitations and doubts.
Secretary Shultz, in short, has a great deal of work ahead. The value of the Lebanese-Israeli agreement cannot be depreciated. But it was only the first and easiest step - one which both parties wanted. Unless the United States can persuade Syria to go along, little will have been changed. Middle East history teaches the danger of drift. To avoid it will take vigorous, creative US diplomacy.