If there is to be a general, enduring Mideast settlement, it will have to begin with a separate, bilateral Egyptian-Israeli agreement. That's the only surviving hope.

Attention is now centered on the imminent meeting of the Egyptian and Israeli foreign ministers in London under U.S. auspices, but in the diplomatic world there is no serious expectations that it will lead to the kind of "comprehensive" settlement that President Anwar Sadat of Egypt and President Carter keep on talking about.

Should a stalemate at London prompt Carter to propose a plan of his own, there is at least an outside chance of achieving a breakthrough if he is prepared to suspend the all-or-nothing approach in favor of pursuing the step-by-step policy so effectively pursued by former secretary of state Henry Kissinger.

The deadlock after the 1973 Yom Kippur war seemed as unbreakable as the current one, with the Arab states (then as now) swearing they would never come to terms with Israel separately.

Nevertheless, Kissinger ultimately persuaded Egypt to make a separate interim peace pact with Israel. Syria, after first denouncing Egypt, soon followed suit. The same sequence or separate agreement also broke the stalemate after the 1948 war.

Ariel Sharon, the former Israeli general turned agriculture minister, not long ago expressed his firm belief that "a peaceful settlement will be reached within a short time," first with Egypt, and later with the others.

On a recent visit to the Middle East and North Africa, I found numerous officials who more or less shared this view.

It is quite apparent that the Begin government is prepared to give Sadat virtually anything he wants for Egypt itself and its national requirements. The sticking points, of course, is Sadat's pretensions to being a pan-Arab spokesman, as if he had a mandate to negotiate a general settlement.

As of today, Sadat has no standing at all with the other interested Arab nations, whose leaders won't even talk to him. Some, in fact, would welcome his overthrow or assassination. Syrian President Hafez Assad has vowed to "wreck" the Egyptian leader's peace "overtures" to Israel.

"The visit of Sadat to Jerusalem," Assad says, was the "most dangerous collapse in Arab history since the Crusades. His visit sacrificed all the interests of the Arabs at the feet of Zionist Israel's agressive objectives." Both Syria and Iraq demanded that Sadat break off all contact with Israel, renounce his peace initiative and admit its failure.

It ought to be obvious by now that even if Sadat somehow got a "comprehensive" agreement with Israel, it would automatically be rejected by the other Arabs. Hence, it ought to be equally obvious to the Carter administration that its efforts should now be directed toward furthering a separate Egypy-Israel agreement.

That, too, may fail, but it is at least possible. Some diplomats have always believed that Sadat would settle for a separate peace if it could be given the appearance - no matter how superficial - of a general settlement. What is needed is new pressure by Carter, not only on Israeli Prime Minister Menachem Begin, but Sadat, to get things moving. If Egypt comes to terms with Israel, Syria and Jordan will have little choice but, as in the past, to join the parade.

A regional settlement achieved by such stages would probably leave the Palestine question in limbo, but then it has been in limbo since 1948 when the British Palestine Mandate was superseded by the first Arab-Israeli war. Actually, once a permanent peace was in place, the Palestine problem could in time fade away, for the Palestine Liberation Organization (PLO) has been financed and kept alive by the Arabs, not out of loyalty to the PLO, but as a weapon against Israel. With peace and Arab-Israeli reconciliation, the PLO could well become an anachronism.

Many Arab leaders, with good reason, hate and distrust the PLO, whose guerrillas almost took Jordan before King Hussein crushed them in the 1970 "Black September" civil war. Since then, PLO forces have done their best to make a corpse of Lebanon, and Syrian troops are even now fighting against them in that helpless, tortured country.

When Sadat went to Jerusalem last November, he told the Knesset that the "Palestinian cause" was the "crux of the problem." But is it? While Sadat and other Arab leaders have often shed crocodile tears over the Palestinians, they conspicuously did not establish an independent Palestinian nation on the West Bank and the Gaza Strip when they controlled those regions between 1948 and 1967.

It's a good moment for Carter to remember that he once said, "It's unfair to the world to blame Israel for the plight of the Palestinians." It is also timely to recall Kissinger's warning: "A Palestinian state on the West Bank is bound to be an element of instability both for Jordan and for Israel. It will compound the crisis, not solve it."