What does the United States do next in the Middle East? This question has to be posed against a background of many months of drift in US policy, and a basic failure to deal with the problems of the region in their full reality.
Since this spring, the Reagan administration has tried to shoehorn all the complexities of the Middle East into the simplistic formulation of ''strategic consensus'' - the drawing together of all friendly regional countries to oppose Soviet encroachment. The concept fared badly. While it was embraced heartily by both Egypt and Israel, primarily as a means of piggy-backing on the shift of US strategic concern from the Arab-Israeli conflict to the Persian Gulf, it was rejected on Secretary Haig's spring visit to the region by both Jordan and Saudi Arabia. In both cases, it was met by new assertions that Israel and the Palestinian problem, not the Soviet Union, are primary threats; and in the latter case it risked telling the Saudis that we are more concerned with their security than they are themselves - a bad bargaining position ever to be in.
At the same time, the pursuit of strategic consensus has largely come down to the desultory debate over AWACS aircraft for Saudi Arabia - debate which, win or lose, is a poor substitute for a policy which looks at all the possible threats to the Gulf and then leads to a coordinated US-Saudi strategy for dealing with them. Trust has suffered; and ''litmus tests'' have replaced a common sharing of concern about the future of the Gulf and ways to promote it.
Further west, the administration nearly abandoned the long efforts in the Camp David peace process which, however tattered, did at least concentrate the minds of most parties in the region on issues of peace instead of renewed conflict and unilateral advantage. We tend to neglect the chastening effect of US leadership in the Middle East, and the vacuum that develops when we neglect that role.
Logic may now argue for soft-peddling the autonomy talks, lest they meet insuperable difficulties and incubate tensions between Israel and Egypt as the critical date approaches next April for return of that part of Sinai remaining in Israeli hands. Why should Israel seek serious talks on autonomy, when it would have most to give up in reaching agreement? Why should Egypt pursue the talks with vigor, if moderate Arab states are prepared to accept the separate treaty with Israel as a fait accompli?
But that logic does not explain everything, and misses the critical need for some continuing peace framework to ratify and sustain what has been achieved so far. It underplays the pressures which will build up on the Mubarak government, both from within and without, as it seeks to demonstrate its grip on issues of war and peace in the region. And it increases the risks that Washington will be under rising pressure, from Persian Gulf states sought for the strategic consensus, to lean on Israel as the price of cooperation with the US.
Perhaps the autonomy talks will ultimately fail. But even if they do, they will prove themselves to be a useful way station to newer ideas; serious efforts to move them forward will concentrate attention on peace as the best alternative to chaos; and they can demonstrate that Egypt, Israel, and the US are genuinely trying to hack away at Middle East dilemmas, even if they do not now succeed.
The first order of business should be for the administration to appoint a senior-level negotiator for the talks - from the available pool of top-flight talent. The second order of business should be the indication of seriousness of purpose in the talks: both about ''legitimate Palestinian rights'' and about Israel's security. Hoping that all will come right in the next few months without such a commitment is a poor basis for policy in a region where trouble is so endemic.
Next, the US should proceed cautiously in further enfolding Egypt in its military embrace. To be sure, more economic aid - especially in league with Western Europe and Japan; certainly, speeding up the delivery of military equipment to Egypt. But to lose a sense of caution about a military presence in Egypt - symbolized by B-52s dropping bombs in the desert as part of the November ''Bright Star'' exercise - may, unless the US is very careful, begin to exceed Egyptian tolerance in protecting its sense of independence and sovereignty. Here , the new Mubarak government should set the pace, however anxious the US is to demonstrate the solidity of the rear echelon for getting to the Gulf.
Finally, it is time to give ''strategic consensus'' a quiet burial, and to begin in earnest the difficult work of defining all the threats to security in the Middle East, in cooperation with friendly states, and to create the complex web of political and economic - as well as military - responses which are needed , both on its own and with its European allies. The Soviet threat is clearly part of that scheme; but concentrating on it alone risks driving out concern with all the other factors which can lead security in the Middle East to come unstuck.
However difficult it is to manage and sustain, a subtle and balanced approach to all Middle East problems beats all alternatives suggested. It offers the best chance of meeting America's many needs there - and they are several: advancing Israel's need for a secure and peaceful future; gaining a fair solution to the Palestinian problem as a critical step to a permanent peace; developing trusting relations with Saudi Arabia and other Gulf states; and enabling President Mubarak to see Egypt's long-term future as lying in continued close relationship with the US, instead of seeing in Anwar Sadat's assassination the lesson that it is perilous to become overidentified with the US, its purposes and policies.