Convinced that the status quo is becoming unsustainable, shaken by Arab-Israeli violence on the West Bank and responding to appeals by such Arab moderates as King Hussein and President Hosni Mubarak, the United States seems ready to undertake another search for peace in the Middle East.

Secretary of State George Shultz is about to leave for the Middle East to see if a peace process can be started up again. He follows Assistant Secretary of State Richard Murphy, who traveled through the area with a proposal that, according to press accounts, envisages early elections to implement self-government for the West Bank and Gaza as anticipated by the Camp David accords of 1978. This is to be part of a negotiation toward an overall settlement in which an international peace conference is to play a significant, as yet undetermined, role.

It is to be hoped that recent violence will enable the parties to resolve the three issues that have defeated them in past autonomy talks: What area is subject to self-government? Who shall govern it? How can Israel's security concerns be met? The answer to these questions will shape a final settlement, for the area under autonomy will almost surely be also the area eventually returned to full Arab sovereignty.

Once the negotiations leave the well-traveled terrain of Camp David, the United States should involve itself only if it is prepared to see the process through to a conclusion. Every agreement negotiated between Israel and Arab parties has had U.S. participation as the indispensable ingredient.

At this writing, an international peace conference is emerging as the deus ex machina of Middle East diplomacy. Its goal is often stated to be contractual peace -- as if peace were a legal concept. But India and Pakistan, and Iran and Iraq, which live in contractual peace, have fought bitter wars and killed more people than Israelis and Arabs. The lesson, then, is that peace emerges not from documents but from concrete conditions; a definition of substance must be the first goal of Middle East diplomacy.

Neither the parties nor the international community is anywhere near a consensus as to what sort of compromise should be sought. They do not agree even on who the appropriate negotiating parties should be. In Israel, the Likud bloc of Prime Minister Yitzhak Shamir is opposed both to an international conference and to any territorial concessions; the Labor alignment of Foreign Minister Shimon Peres favors both, but it is afraid to put forward concrete ideas lest it lose support in the forthcoming Israeli elections. In the Arab world, moderates ask for the '67 frontiers, including the return of the Old City of Jerusalem; radicals oppose any settlement with Israel. The Soviet Union supports an international conference, the political program of friendly radical Arab countries and undefined international guarantees. The other permanent members of the Security Council advocate a conference and see no sense in risking Arab friendships by deviating from Arab positions.

Then there is the problem of what to do about the Palestine Liberation Organization. It will be traumatic for Israel to cede any part of the West Bank. To see established there an entity whose program throughout its history has included the destruction of the Jewish state is both unwise and beyond the competence of any foreseeable diplomacy. Whatever legalistic formulae may be conceived will be rejected by significant, violent factions of the PLO, and those who pay lip service to them will not be permanently satisfied with the part of Palestine that could become theirs under any foreseeable territorial compromise. King Hussein, the target of several PLO attempts to unseat him, and conscious of his inability to negotiate a common bargaining position with Yasser Arafat, knows very well that he would be once again the first target of PLO expansionism.

The irreconcilable positions of the parties, the ambiguity of the Soviet position and the differences with our European allies are supposed to be overcome by a conference where all the parties can exhibit their incompatibilities. The model, we are told by advocates of the conference, is the 1973 Geneva conference, which met in plenary session only once. Thereafter, several agreements were negotiated between the parties under American auspices, culminating in the Egyptian-Israeli peace accord. Israeli officials have claimed that there exists an agreement between Israel and King Hussein (which he has never confirmed) to confine such a conference to a ceremonial opening role after which concrete issues will be negotiated bilaterally between Israel and the relevant Arab party. And America apparently has promised Israel that the bilateral talks cannot be referred to the plenary session without the consent of both parties and that if Israel decided to withdraw from the conference, America would walk out too.

These procedural devices cannot possibly prevent the isolation of the United States, or of Israel for that matter. To begin with, the current situation is not even remotely comparable to 1973. Then, Israeli troops were astride the Suez Canal and 12 miles from Damascus. The United States alone was in a position to alter that state of affairs. Its substantive program was buttressed by the argument that there existed no alternative to American mediation. A great Arab statesman was prepared to stake his prestige on the step-by-step approach.

None of these conditions exists today. Israel is deeply divided; no Arab leader is in a position to undertake solitary initiatives. The idea that Israel and the United States could walk out of an international conference together is naive. In the unlikely event that the United States would join such a desperate gesture, it would only mean a change of venue. For the United States could not possibly accept a prohibition against continuing talks in normal diplomatic channels or through special emissaries.

The idyllic picture of an international conference proceeding to a conclusion through a give-and-take in bilateral negotiations is a mirage. Deadlock is the almost certain result of direct talks, after which there would be increasing pressure on the United States to break the deadlock based on the same arguments used to assemble the conference in the first place.

The United States must not delude itself. Most advocates of a conference want to use it to maneuver America into imposing a settlement. The Soviet Union, in particular, is receptive because a conference would restore it to a central role in the Middle East and enable it to take credit for having made America induce Israel to yield. Soviet participation therefore could be constructive only if the Kremlin were prepared to sponsor a genuine compromise -- in other words, if it would ask the same sacrifice of its radical Arab allies that a conference will undoubtedly expect of America's friends. The same, to a greater or lesser extent, is true of the other permanent members of the Security Council. If America wants to avoid being isolated, accused by the majority of acting as Israel's lawyer and by Israel of betrayal, it must obtain clarity about substance before a conference from all parties that seek to participate.

In these exploratory talks the U.S.-Israeli dialogue is especially delicate. The United States clearly has an obligation not to weaken the security of an old, reliable, democratic ally. But it cannot perform this role unless Israel speaks with the approximation of a single voice. The incompatible positions of the prime minister and the foreign minister will put a nearly impossible burden on even the most well-intentioned U.S. government.

The ideal interim solution would be a unilateral Israeli initiative declaring its readiness to place Gaza and certain heavily populated areas of the West Bank under Arab control and inviting negotiations to discuss governance and security arrangements. Since Israeli divisions almost certainly preclude this, negotiations under American auspices would be the best approach. But, whatever the forum, even if matters have gone too far for a unilateral American effort, the focus of American diplomacy must be on establishing a substantive framework.

The following principles should be part of such a framework:

Israel must face the fact that it cannot permanently occupy territory inhabited by a reluctant population.

The Arab parties must give up the illusion that they can achieve their maximum program simply in return for accepting the state of Israel. Everywhere else, recognition is the beginning of diplomacy, not the end of it. For Israel to return to the 1967 frontiers would leave it in the position of Czechoslovakia after Munich. The corridor between two of Israel's principal cities, Haifa and Tel Aviv, was 10 miles wide before the 1967 war. It would be indefensible under modern conditions. ''Minor rectifications'' -- the sacramental formula -- is too imprecise. The criteria must be security and defensibility.

Guarantees by outside powers cannot be a substitute. The challenge can always be kept below the threshold of unambiguous threat. And guarantees can be used as a lever to prevent retaliation for fear of jeopardizing the guarantee. Moreover, an international guarantee is almost always subject to a veto by one of the guaranteeing powers.

The city of Jerusalem cannot again be divided, though a special status for the Holy Places and ensured access to them is essential.

The areas ceded by Israel must be demilitarized under an inspection system in which Israel participates.

Either Jordan or a consortium of moderate Arab states must assume responsibility for the civil administration of Gaza and those West Bank territories given up by Israel. Obviously, Palestinians will play an important role in such an administration, but not the PLO as a political organization.

The task of American diplomacy is to get from all parties in advance of any international conference an agreement that sacrifices and compromises are essential for progress toward peace. Only if that is done can an international conference make sense. Otherwise, the United States is far better served by unilateral initiatives.