Even a year ago . . . the nation of Israelis and Arabs engaging in face-to-face negotiations about real peace . . . seemed like an illusion. Yet today such negotiations are within reach - and I am proud of the progress that has been achieved by all nations concerned to make this dream possible.

President Carter.

THAT'S HOW the President was appraising Mideast peace prospects in a speech to the World Jewish Congress on Nov. 2, one week before Egyptian President Anwar Sadat made his celebrated offer to go to Jerusalam to talk peace face-to-face with Israeli Prime Minister Menahem Begin. We are not suggesting, of course, that Mr. Carter was expecting things to work out that way. We are merely noting that the Jerusalam breakthrough was not inconsistent with the stated purposes of recent U.S. policy. ANd we would go further: It is hardly likely that Mr. Sadat would have been emboldened to make the first move - or Mr. Begin to receive it so well - if the United States had not been wheedling, cajoling - and sometimes shoving - the parties toward Geneva at a time when a reconvening of the Geneva conference was almost universally thought to be the only way open to get some movement toward a peaceful settlement.

One can question whether, in these exertions. Geneva did not become almost an end in itself, or whether the joint U.S. Soviet statement earlier this year was the right shove at the right time. But it seems to us to distort the real significance of Jerusalem to treat it as a rejection of either past American policy or future American influence. That's not only been the cry of some of the administration critics; administration officials themselves seemed needlessly fearful, in the days just after President Sadat's announcement, that they had suddenly lost their grip on a diplomatic process they had come to think was primarily theirs to shape and direct. Presumably, President Carter's measured tribute last week to Jerusalem's "tremendous accomplishement" can be taken as evidence that the administration has regained its poise. At any rate, we think Mr. Carter put the matter just right in his news conference last week:

When there has been no progress being made, the United States has taken the initiative. Now that progress is being made, a proper role for the United States is to support that progress and to give the credit to the strong leadership that has already been exhibited by Prime Minister Begin and President Sadat and to let our nation be used as called upon to expedite the peace process.

That statement, it seems to us, restores a badly needed sense of continuity U.S. policy, and to the Mideast scene as well, at a moment of extraordinary - and unsettling - uncertainty when it is not easy to sort out what is fundamentally new from what is familiar and consistent with past. In Tripoli, for example, the would-be spoilers of the new Egyptian Israeli connection have been postruing and fulminating for four days without being able to agree on just how the spoiling should be done. And that is now lnew. The LIbyans, the Iraqis and the Algerians, and the rest, who are once or twice removed from actually having to fight a Mideast war, have always been better at urging others to excesses than at doing anything - let alone anything constructive - on their own.

It is also not new, in the sense that it is not surprising, that the Syrians have apparently been relatively restrained at Tripoli; the Srians, who do get caught up in Mideast wars, cannot afford quite so lightly to foreclose the prospect of peaceful settlemen. That they, along with the Jordanians and the Saudi Arabians for their own reasons, have refused an invitation to the mid-December meeting of the Israelis and the Egyptians in Cairo was also quite predictable. All the old familiar conflicts over borders and security and the grievances of the Palestinian Arabs are still very much with us, and even some of the more moderate Arab states could be expected to take their distance from the Sadat initiative for a time.

What's new, of course, is that in Cairo this month the Egyptians and the Israelis will give outward evidence at a lower working level that there was much more than symbolism to their Jerusalem summit - we do not doubt that there are other, continuing contacts as well. And this developing normalization of working relations, if it moves along toward a tentative - but potentially permanent - Israeli-Egyptian settlement and on agreement in principle between the two of them on broader issues, has the capacity to transform the Mideast conflict in two profoundly important ways. To the extent that it is actually able to reduce the threat of a war with Egypt, it could be expected to encourage Israel to do the hard "rethinking" of its security requirements on the West Bank and elsewhere that some Israelis are already calling for. And it could likewise be expected to cause the other "confrontation" states and the Palestinians to reflect upon the prospect of trying to advance their interest, and confront Israel militarily,without Egypt's automatic and all-important support.

This is the fundamentally new chemistry of the Middle East conflict, and nobody can safely predict its ultimate results. The "rejectionist" in Tripoli are only one reminder that there is lot of the bad old chemistry still at work. As for the projected Cairo meeting, while it is the expression of new chemistry, the fact that an American delegation will attend also says something about continuity. What it says is that,for all the initial hand-wringing about the Sadat initiative and the future role of the United States, this country is going to continue to have a critical catalytic effect on the course of Mideast events.