In its view of the world following the assassination of Egyptian president Anwar Sadat, Israel has become more apprehensive about the drift of U.S. policy in the Middle East than about the direction Egypt is headed a month after the death of its peace-making president.

Despite an initial bout of nervousness brought on by the quickly closing deadline for final Israeli withdrawal from the occupied Sinai Peninsula, Israeli leaders, from Prime Minister Menachem Begin on down, are relatively sanguine about Egypt's new president, Hosni Mubarak, and appear to be genuinely convinced that Egypt will adhere to the letter and spirit of the Camp David peace accords.

But they appear to be just as genuinely perplexed at the interest shown by some senior figures in the Reagan administration in the eight-point peace plan advanced by Saudi Arabia, and are anxiously watching each day for some kind of dramatic and conclusive U.S. reaffirmation of the Camp David process and an unmistakable repudiation of the Saudi proposals.

What has particularly confused the Israelis is the timing of the Reagan administration's expressions of interest in the Saudi plan, so long after the initial U.S. official indifference when it was first proposed by Saudi Crown Prince Fahd last summer.

What is not clear to the Israeli policy-makers is whether the U.S. interest is merely an extension of the bitter struggle for approval of the sale of radar surveillance aircraft to Saudi Arabia, an expression of a natural tendency to see a glimmer of hope in any Middle East development, or, in the worst case, whether it represents an incipient but fundamental deviation from the Camp David process.

Whatever the case, Israeli sources emphasized, it will take a major U.S. gesture to shore up Israeli confidence in the Reagan administration's commitment to carry on with the Camp David agreement.

This commitment could come in an unequivocal assertion by the U.S. administration, preferably from the president himself, that the United States does not support the Saudi peace plan and regards it as debilitating to the Camp David process, senior Israeli sources said. Or, they said, it could come by "adding deed to word" and sending a senior U.S. official, such as Secretary of State Alexander M. Haig Jr., to the next session of negotiations on Palestinian autonomy, scheduled to start Nov. 11 in Cairo.

Deputy Foreign Minister Yehuda Ben-Meir said in an interview today that statements favorable to the Saudi plan made by officials of the stature of Haig and Defense Secretary Caspar Weinberger foster a perception in the Arab world of a lack of consistency and perseverence in U.S. Middle East policy and seriously undermine both the Israeli and U.S. position in the autonomy negotiations.

"What chance do we have to reach agreement on autonomy if you create illusions among the Arabs?," Ben-Meir asked, adding, "It creates a negative climate. When the Europeans do this, it's one thing. When the United States does it, it is quite another thing."

"How do you expect your negotiating position to be taken seriously if at the same time you're talking about an entirely different peace process," he asked.

Ben-Meir noted what he called "contradictions" in statements by Reagan administration officials about the Saudi proposals and said the Israeli government has been only partially reassured by U.S. statements of continued support of the Camp David process.

Yesterday a senior administration foreign affairs official in Washington commented that "the Israelis will come to realize shortly that we support the Camp David accords as the peace process for the Middle East."

Ben-Meir, and other Israeli officials, stressed that support for Camp David and any part of the Saudi proposal are not mutually compatible because, in the Israeli view, the Saudi plan implicitly rejects recognition of Israel since the name of the Jewish state is never mentioned in the eight points.

Ben-Meir rejected interpretations of the Fahd plan that say recognition of Israel is implied in the Saudi's stated acceptance of the right of "the states of the region" to exist. He said public statements by Saudi leaders since the peace plan was advanced make it clear that recognition of Israel would be preconditioned on acceptance of all eight points, which the Israelis believe would cause the eventual destruction of Israel.

Begin has rejected the Saudi proposals as a "formula for the liquidation of Israel." Along with the rights of "the states of the region" to exist, the plan calls for Israeli withdrawal from occupied territories, establishment of a Palestinian state in the West Bank and Gaza Strip, Arab sovereignty in East Jerusalem and removal of Israeli settlements from the West Bank.

Keeping up the pressure on the United States, Defense Minister Ariel Sharon and other ministers have been conducting a coordinated campaign of charges that the United States is contributing to Middle East instability by indirectly supplying arms to Iraq through Jordan and Saudi Arabia.

Ben-Meir repeated that theme, saying, "It's a repeat of the Iran syndrome: big sales of weapons, construction of sophisticated defense systems and then not knowing where that stuff is going or how long the regime will last. It's more serious than Iran, because at least Iran had a political process then."

The United States denied it is supplying arms indirectly to Iraq, but Sharon replied that he can provide proof. Today, reports were leaked to the Israeli press by Defense Ministry officials that U.S. ammunition, antitank missiles, spare parts for armored vehicles and communications equipment have been routed to Iraq through the Jordanian port of Aqaba.

Sharon intensified the pressure when his office announced that the defense minister had decided to postpone a visit to Washington later this month to discuss U.S.-Israeli strategic cooperation.

However, Begin told the parliament tonight that the strategic cooperation talks would procede, and that Sharon would meet with Weinberger in Washington on Nov. 30.

The parliament, by a 55-18 vote, with 27 abstentions, adopted a resolution rejecting the peace initiatives of both Saudi Arabia and the European Economic Community and reaffirming Camp David as the sole basis for a Middle East solution.

Referring to Syrian missiles deployed in Lebanon, Begin told the parliament the missiles could be destroyed by Israel in two hours, but that Israel would continue to use restraint, especially while U.S. special envoy Philip C. Habib is in the region later this month.

"Were the missiles preventing us from carrying out surveillance flights over Lebanon we would not wait for a visit from anyone. Though it is true they cause us some problems, up to a point, they do not prevent us from carrying out surveillance flights over Lebanon and we do so almost daily," Begin said.

Because it is axiomatic in Israeli foreign policy to treat any perceived national security threat, no matter how incipient, as if it had imminent consequences, it is difficult to gauge whether Israel's reaction is based on real fears of a U.S. deviation from Camp David and the acceptance of a key role for Saudi Arabia in future peace processes, or whether the Israeli reaction is merely following the book.

Neither Begin nor his advisers have been willing to speculate on the motive of the U.S. interest in the Saudi peace plan, and have confined themselves to saying whatever the motive, it is misguided.

One Foreign Ministry official, who asked not to be named, suggested, "Maybe the Americans think that now that the Saudis got what they wanted the arms package they are in a position to play a more moderate role in the peace process. We don't agree with that, but maybe that is the Reagan administration's thinking."

Whatever the U.S. motive, in the Israeli view, attention to the Saudi proposals comes at an awkward time when the Israeli government had just attained peace of mind about post-Sadat Egypt and the future of the Camp David process.