WHAT LEBANON needs is quite clear and quite hard. It needs all the help it can get in removing foreign forces, Israel's, Syria's and the PLO's. But the Lebanese are out of the habit of self-restraint, and so that they do not simply resume their mutually murderous ways, those foreign forces must be replaced by a larger, more vigorous peacekeeping unit supported by many nations. The two steps must go hand in hand.

To be sure, this has been the plan for Lebanon since last summer. The difficulties of putting it into effect, however, have loomed larger since it became evident that the withdrawal target of the end of the year was a fantasy. A certain level -- not the old high level -- of sectarian strife and local insubordination has resumed, and talks on foreign withdrawal have yet to get off the ground. There is a tendency in some quarters to flee from the sheer disagreeableness of the situation into a simple critique of one party, mostly Israel.

The criticism is typically exaggerated and nasty. The fact is, however, that Israel does have a whole other and higher priority than seeing Lebanon made healthy and whole again. It is to remake Lebanese-Israeli relations. One can understand why the Israelis, having paid in blood, treasure and international standing for their invasion, should want to set the price of their withdrawal. Lebanon, however, is the victim state. The Israelis can reasonably ask to coordinate their withdrawal with Syrian and PLO withdrawal and with entry of an enlarged multinational force suitable for, among other purposes, ensuring the security of the Israeli border. They cannot expect to dictate the terms of a new Israeli- Lebanese political relationship, which will be flawed precisely as it is extracted under duress.

Does the United States really want Israel and the others out of Lebanon? The answer stated by officials is yes, but a different answer is indicated by American hesitancy to accept the implications of the Lebanese government's frailties. First among these implications is the requirement for a beefed-up multinational force, not just around Beirut but in southern Lebanon and also in the north, where PLO forces now guard some 50,000 Palestinian refugees. The gaps in the protection available from the Lebanese army can be filled only slowly. Until then, international peacekeepers must serve. The United States is not and should not be the only provider, but it cannot shun a principal role. The assurance that it will carry its full share of the load is the best help the administration can give to its chief negotiator, the redoubtable Philip Habib, who is now back in Beirut.