In dealing with Anwar Sadat of Egypt and Menahem Begin of Israel, Jimmy Carter is indulging in personal diplomacy to a degree that would have brought blushes to the not-exactly-immodest cheeks of Henry Kissinger. Already the president is showing the telltale signs - leaking materials that make him look good at the expense of his negotiations.

But because he is more a moralist than a strategist, because he cares more about cordial relations than diplomatic outcomes, Carter is not nearly as effective as he seems to think in personal diplomacy. The chances for peace in the Middle East after his latest encounters are about where they stood before he met with Sadat and Begin.

Begin came to Washington before Christmas bearing an Israeli statement. Judging by Israel's past performance, at least, the statement was remarkably generous.

It did not ask for territorial concessions, even of the minor kind that the United States had always thought justified. It provided for total return of the Sinai Desert to Egyptian sovereignty. It provided for Palestinian self-rule over the whole of the West Bank and the Gaza Strip. It implied reversion of the Golan Heights to Syria. While there were reservations regarding Jewish settlements in formerly occupied territory, and with respect to Palestinian statehood, both issues were subject to negotiation.

Carter said the Israeli position was "constructive." He also said the Israelis should show more "flexibility." That, in effect, was saying to the Egyptians that Begin's position was only an opener, subject to big change by negotiations.

When Sadat and Begin met in Ismailia on Christmas Day, Begin laid down his proposals. Because of Carter's comment about flexibility, he was in no position to put them forward as the generous offer they in fact were. On the contrary, he was immediately on the defensive before Egyptian demands for concessions on settlements and Palestinian self-determination.

Begin did not himself yield, and further meetings of the foreign ministers produced only slight progress. So Sadat broke off the political talks on Jan. 18. He headed for Washington, threatening to break off the talks entirely if he didn't get more Israeli concessions and military assistance from the United States.

What the Egyptian leader needed in those circumstances was, as they used to say on the "Lone Ranges," a cloud of dust and a hearty "Hi-yo, Sadat." The "Hi-yo, Sadat" would have meant laying on the flattery and the banquets in a way that bucked up his spirits and made him come out of his corner like a tiger for new talks with Israel.

The cloud of dust would have jumbled together the issues of settlements and self-determination and Israeli withdrawal in a way that defied analysis and softened animosity. The ground would then have been beautifully prepared for an Israeli-Egyptian statement of principles. Sadat could have passed that off to the other Arab states as a framework for further talks, and then himself entered into direct substantive negotiations with Israel.

Instead the president met the agenda of the Egyptian leader point by point in a pedantic, even defensive, way. He tried to make Sadat feel good not by laying it on thick (indeed, as some Egyptians remarked, there were no banquets) but by lining up with Egypt on particular issues - especially settlements (where he leaked documents to prove his good faith), Palestinian self-determination and more arms.

In return for give on particular issues, the president slowed down Sadat's rush diplomacy. He got the Egyptian leader to agree to a resumption of talks with Israel on a general statement of principles through the medium of Assistant Secretary of State Alfred Atherton, who will now undertake a shuttle between Cairo and Jerusalem.

My guess is that Atherton can finally put together a general statement. But is will be long and difficult going because hard issues have been sharpened, not obscured, and the Israelis have been angered by Carter's tilt toward Sadat.

That kind of outcome hardly needed the active intervention of the president himself. Secretary of State Cyrus Vance could have done it easily, or maybe even Atherton.

Unfortunately, the president does not realize that he performed in a pedestrian way. He seems to think he is a terrific whiz at personal diplomacy. And sadder still, none of those around him have the strength to tell him that in foreign policy, as in so many other matters, he would be far better off if he delegated authority to others.