Sadat-to-the-rescue emerges once again as the theme of the drama. The action turns on progress toward peace in the Mideast. In the process, Jimmy Carter receives political help, and history saves a place for Menachem Begin. That at least is the scenario brought to my mind after a long session with Sadat on the eve of the Washington talks he and Begin will be having separately with Carter this week and next.

The Egyptian president received me at his villa adjoining the dam across the Nile just outside Cario. He seemed fit and in good spirits, and he was, as usual, elegantly dressed in a dark blue double-breasted suit. We sat outdoors under a tree. "I'm just a villager," Sadat said in the tone of the country boy who has fooled every city slicker in the world.

I asked Sadat whether, as I had heard in Washington, he had pushed for the invitations that are bringing him and Begin to visit Carter. "Carter phoned me and extended the invitation," Sadat replied. That suggested a political motive, and I asked the Egyptian president his feelings about the coming election in the United States.

His reply was formal. "I am very happy and satisfied to work with Carter.

But it is the decision of the American people. I have nothing to do with this."

Begin, Sadat said, had been "scrupulous" in meeting Israel's obligations to Egypt under the peace treaty worked out at the Camp David talks. But he had hung back when it came to fulfilling the Camp David agreement on "autonomy" for the Palestinian Arabs residing in the Gaza Strip and on the west side of Jordan River. Sadat cited various obstacles put in the way by Begin, including the insistence on the right to build new Jewish settlements. He said:

"All the signs confirm that the man wants his role to end here. He wants to stop in the middle of the road. He wants it stated in history that he is the man who achieved peace with Egypt. But he will be very wrong, because [the man] who comes after him will have the whole credit."

As to exactly how the difference between Israel and the Palestinians might be settled, Sadat showed the kind of pleasant vagueness that is probably appropriate to heads of state on matters of such fine detail. He spoke of a "political directive" that would be issued by himself, Begin and Carter to to their ministers.

The "political directive" would "define" the content of automony. It would require concurrence by the Palestinian Arabs for new Jewish settlements -- thus in effect freezing the settlement issue. It would reserve Arab rights to East Jerusalem. It would define in detail Israel's security needs. The Israelis would be allowed to station troops in certain stipulated areas. They would be guaranteed against Arab Palestine's becoming an independent state for at least five years. But they would not be able to use "security" as an excuse to prevent the passing into Palestinian hands of such matters as health and sanitation and water rights and land tenure.

The prospect that the Palestinians would refuse even such a formual does not seem to bother Sadat. "I shall never speak for the Palestinians," he said. "My job and, I think, Carter's job and Begin's is to put them on the right approach. We have to do our job."

As to whether Begin will eventually accept something that can be called autonomy for the Palestinians, Sadat seems to be genuinely unsure. "I have heard people say he was against it. But I don't know, I wonder, I really wonder."

If Begin is tempted, Sadat will undoubtedly make it easier for him. The Egyptian president is flexible about details and about timing. He has kept the subject matter purposely vague. If the Carter-Begin sessions that follow the Carter-Sadat meetings bear fruit, there is already scheduled, for April 21, a meeting in Washington of the principal negotiators -- U.S. Ambassador Sol Linowitz, Egyptian Prime Minister Mustafa Khalil and Israeli Interior Minister Josef Burg. If that session succeeds, presumably there would be a replay of the Camp David summit that all three leaders could claim as a triumph.

For Israel, the vagueness of the Sadat approach presents grave risks. The larger consideratons of geography and population require that Israel live dangerously. It is far better to face the perils one at a time now, than later when they may all converge and when that most courageous and farsighted of leaders, Anwar Sadat, is no longer in position to ride to the rescue.