Egyptian President Anwar Sada, who has staked his political career on proving to the Arab world that peace with Israel is both possible and beneficial, has suffered another major embarrassment to his controversial policy in the attack on Iraq's nuclear reactor, in the view of Western and Egyptian analysts here.

The Israeli attack near Baghdad has infuriated and humiliated the entire Egyptian political leadership, coming as it did only four days after Sadat's meeting with Israeli Prime Minister Menachem Begin at Sharm al-Sheikh at which Sadat, with seeming success, had urged the Israeli leader to exercise restraint in Lebanon.

The latest Israeli action, according to analysts, here, can only serve to plunge Sadat back into isolation and discredit in the Arab world. He had been overcoming this through his initiative in getting Begin's promise to give the United States ample time to find a peaceful solution to the Syrian missile crisis in Lebanon.

Sadat also called on Begin to halt Israeli attacks on Palestinian guerrilla positions in Lebanon. While the Israeli leader did not give his public approval to this at the meeting at Sharm al-Sheikh, at the southern tip of the Sinai Peninsula, observers here note there have been no major Israeli raids on Palestinian positions in Lebanon since then.

Now, whatever points Sadat might have scored in the Arab world by his intervention with Begin on behalf of the U.S. peace initiative and Palestinians in Lebanon seem certain to be lost in the general Arab outcry over the Israeli attack on Iraq's nuclear power plant.

Once again, Sadat has been made to look a fool in Arab eyes by his policy of courting Israel and insisting that peace with the Jewish state can be a paying policy, according to these analysts and some American diplomatic sources seriously concerned about the eroding effect the Israeli action may have on the Egyptian leader's stature at home and abroad.

Western and Egyptian analysts believe there is little of substance Sadat can do now to show support for Iraq or the Arab cause without jeopardizing his hopes of getting back the remainder of the Israeli-occupied Sinai next April as called for in the Camp David accords.

Other than a state of unusually harsh statements from Sadat and his lieutenants, there is no sign so far that the Egyptian leader is contemplating concrete retaliatory action. Negotiations among Israeli, Eyptian and U.S. officials over arrangements for Israel's final withdrawal from the Sinai got under way in Tel Aviv this week as if nothing unusual had happened.

There had been some speculation here that Sadat might call off the talks and order the Egyptian delegation home to protest the Israeli attack on the reactor. But the most Sadat may do, according to Western diplomatic sources here, is to put off announcement of a final agreement with Israel to avoid more criticism from Arab countries for his peace policy.

Meanwhile, Sadat has attempted to protect himself from such criticism by warning Israel that its "agression" against Iraq holds "grave consequences" for peace in the Middle East.

"Such actions," he said, "are inconsistent with the requirements of this critical stage of the current efforts for reaching a comprehensive peace as the only way for a more stable and reassuring future."

While he spoke of "grave consequences" and "more obstacles" on the road to an overall peace settlement, Sadat did not spell out what these might be.

Egyptian Foreign Minister Kamal Hassan Ali called on the United States to take some action to present Israel from "perpetrating death and destruction" in the region.

Western analysts and some Egyptian officials said this line of diplomacy -- urging the Reagan administration to take punitive steps against Israel for its raid on Iraq -- may be the main Egyptian reaction at this point.

"What can we do?" asked one Egyptian official noting the difficult situation in which Sadat now finds himself with Israel. "It is up to the United States."

This is not the first time Sadat has been embarrassed by the Israeli government since his signing of a peace agreement with the Jewish state in March 1979. Last August, the Egyptian leader felt obliged to break off talks with Israel over Palestinian autonomy after the Israelis annexed formerly Arab East Jerusalem and declared it unified with West Jerusalem as their capital. The status of Jerusalem was to have been the final issue to be jointly discussed under the Camp David accords.

The Israeli action caused an uproar throughout the Arab world and Saudi Arabia called for a jihad, or holy campaign, against Israel in retaliation. The autonomy talks have yet to resume, although Sadat said at his meeting with Begin last week that they would resume after the June 30 Israeli elections.

Sadat said he would meet with Begin or whoever wins the Israeli elections in July, presumably to discuss the resumption of autonomy talks and possibly also to announce a final agreement on arrangements for Israel's withdrawal from the Sinai and the establishment of an international peacekeeping force.

Whether Sadat will now go ahead with this meeting despite the Israeli raid on Iraq remains to be seen, but he has repeatedly indicated he does not intend to allow himself to be dissuaded from his peace policy with Israel because of temporary difficulties.