Disappointed Sadat hangs on to Camp David-grimly

"Terribly disappointed," "betrayed," "frustrated," "disgusted" -- these are the words Egyptian officials use to describe the mood of President Anwar Sadat as he prays and fasts during this Muslim holy month of Ramadan.

But if the Egyptian leader is agonizing over the havoc done to his cherished peace initiative by the Israeli attack on Beirut and the subsequent fighting in Lebanon, he has so far kept it to himself.

A senior presidential aide said Mr. Sadat is not thinking of venting his wrath in any way that would disrupt either his relations with Israel or the peace process in general. He said there will be no retreat from the Camp David accords and that, eventually, the negotiations on Palestinian autonomy for the West Bank and Gaza will be resumed.

"We still believe that we are the party that has made the initiative for peace and opened the door for hope in the region," he said. "Because of that responsibility, no matter how disgusted we are, we cannot afford to be carried away by our disappointment or disgust to the extent of giving up hope.

"The President believes he has to continue with the process, whether with Israeli Prime Minister Menachem Begin or someone else, whether with immediate results or not. He can't afford to lose hope because the objective is so important, so vital to the people of the Middle East. And he's paid so much for it already that he just can't give it up as long as he feels that things can still be done."

But for President Sadat, Israel's repeated assaults on Lebanon have served to refute his theory that the peace treaty with Egypt would inspire the Israelis to negotiate with the rest of the Arab world and the Palestinians. At peace with its most powerful Arab neighbor, Mr. Sadat had dreamed, the Israelis would feel secure enough to rethink their relationship with the Palestinians and with countries like Jordan and Syria.

Instead, the President's critics have been saying, Israel has exploited Egypt's neutral- ization by expanding Jewish settlements on the West Bank annexing east Jerusalem, raiding Iraq, and now bludgeoning the Palestinians and the Lebanese in brutal military operations that exceed the bounds of legitimate self-defense.

Rather than nurture a bold, magnanimous Israeli leadership, Mr. Sadat's initiative is seen as having actually encouraged Prime Minister Begin. Freed from a military threat from Egypt, to act out his antagonism toward the other Arabs and the Palestinians. And the President will now have a hard time finding many Arabs or Palestinians who will take him seriously should he argue that their interests, and not just Egypt's, have been served by Camp David.

For Egyptians, the gain that can be claimed from sticking stoically to the principles of Camp David, as Mr. Begin appears before world opinion to have grown indifferent to them, is the deepening estrangement of Israel from the US and Western Europe.

The Egyptians believe that sooner or later international censure will have an impact on Israeli policy.

For most outside observers, however, the key to Mr. Sadat's seemingly inexhaustible tolerance is his determination to retrieve the final third of the Sinai peninsula that Israel is scheduled to hand back next April. Between now and then, according to this analysis, he will do nothing to provide the Israelis with an excuse to delay the return of Egyptian sovereignty over all of Sinai.

Egyptian officials, of course, resent this interpretation. They argue that Egypt has determined that negotiations are the most practical means not only to retrieve Sinai, but also to ensure the Palestinians their right to political self-determination.

Among some senior officials there is said to be a suspicion that Prime Minister Begin never really wanted to sign the Camp David accords in the first place. There is thus a feeling that he may actually be testing Cairo, looking for the slightest cause to renege on the steps taken thus far toward Palestinian autonomy. In this light, Egypt's reluctance to make any menacing gestures that might provoke Begin becomes a bit more comprehensible.

If there is a limit to the President's patience, it will apparently be reached in accordance with decisions made and measures taken in Washington, not Jerusalem.

"Even if the Israelis continue to be totally negative in their attitude," said a presidential aide, "our hope will be sustained according to the degree of commitment from the US."

While Mr. Sadat is said to have taken consolation in the revulsion at Mr. Begin's policies that is mounting in Washington, he believes the US response to date has been inadequate. Officials here fear that unless the United States is prepared to show more resolution in dealing with Israel, President Sadat's argument that the US can now be counted on as an even-handed negotiating partner will be seen to be fatuous.

At the Foreign Ministry, officials are annoyed and incredulous at what they consider to be America's maddening reluctance to discipline the Israelis. "The US is doing absolutely nothing," snapped one senior official, who dismissed President Reagan's decision to delay delivery to Israel of 10 F-16 fighter planes as "the least the US could do, the minimum."

The point made here is that by failing to confront Mr. Begin with any credible threat, the Reagan administration is destroying America's stature in the Middle East.

"Can America say anything now to make anyone in the Arab world believe that the Soviet Union poses the greatest threat to our security?" asked one indig nant official.