No matter what Israeli Prime Minister Menachem Begin offers during his current visit to Washington, the outlook from Syria on prospects for a negotiated peace settlement in the Middle East is decidedly gloomy.

The most optimistic analysis among Syrian officials, other informed Arabs and experienced diplomats is that even if a Geneva conference meets, it will be only the beginning of a long, arduous process that could just as easily fail as succeed.

For Syria, the immediate concern appears to be to restrain the Egyptians, who in their eagerness to go to Geneva in October have already offered or hinted at more concessions than Syria is prepared to make.

"The Egyptians are going too far too fast, they have played all their cards before the game even starts," a Syrian source complained.

Syria fears that Egyptian President Anwar Sadat, economically dependent on the United States and Saudi Arabia and beset by internal uprest, may feel complained to make a deal that is unacceptable to Damascus, as he did in the Sinai II agreement of 1975.

The Syrians say they are willing to go to Geneva to negotiate the details, but not the principles, of a settlement. They would consider the establishment of demilitarized zones along their border with Israel and the installation of a U.N. buffer force. Diplomatic sources say the Syrians would even accept a staged Israeli withdrawal from Arab territories occupied in the 1967 war, if the agreement specifies that this withdrawal be total and the timetable spelled out.

The principle of full Israeli withdrawal is not open to discussion, the Syrians say, nor is that of recognition of "the legitmate rights of the Palestinians." Since they see no sign that Israel will accept this, and are themselves unwilling to grant Israel the diplomatic recognition it wants as part of an agreement, the prospects for an accord are slim.

"Our differences with Israel are differences of substance, not of form," said an assistant to President Hafez Assad. "We say a settlement is reachable, but on the basis of certain principles. Other things, such as open borderes and diplomatic relations, those are irrelevant now. The question is whether the Israelis will pull out and give the Palestinians their rights or not."

The Syrians take it for granted that there can be no Geneva conference without palestinian participation. They favor the idea of a single delegation to represent all the Arabs, according to diplomatic sources, partly to overcome Israeli objections to negotiating with Palestinians but also to prevent the Egyptians from negotiating separetly.

Western diplomats accept the Syrian view that Damascus would enter the negotiations holding a stronger hand than Cairo.

In contrast to Egypt, Syria has retained good relations with the Soviet Union and is reportedly continuing to receive Soviet arms supplies. Assad could increase tension throughout the region by lifting some of the restrictions he has imposed on the Palestinian guerrillas and by making difficulties over the renewal of the United Nations truce-supervision mandate on the Golan Heights.

syria, however, has between 20,000 and 30,000 of its best troops tied down in Lebanon, and even if Assad brought them back - which it is understood he would like to do - Syria is not believed capable of waging an offensive war against Israel - certainly not without Egyptian participation.

Furthermore, there is suspicion here that Assad would be vulnerable to a bold gamble by the Israelis. If they were to offer to return all the Syrian territory they hold on the Golan Heights, in exchange for Syrian acquiescence to a continued Israeli presence elsewhere in the occupied territories, some analysts believe that Syria would have to say yes.

"Golan is a national wound that must be healed," a well-place Syrian said. "This would put Assad in a very difficult position."

Egypt and Syria set up a "joint political command" last winter in an attempt to coordinate their negotiating positions and prevent the Israelis from playing them off against each other, but Syrian officials say it amounts to little and is not to be taken seriously.

Syrian officials and Western diplomats here say that barring a major breakthrough in Begin's talks with President Carter, Secretary of State Cyrus Vance is in for an uncomfortable reception when he comes back to Syria next month. Syrian expectations were raised by Carter's earlier comments on the outlines of a settlement, and Damascus wants to know if the United States is going to deliver.

"Carter has been talking of a Palestinian homeland," a Syrian source said. "Now they are going to take Vance up to the map and ask him, 'All right, where is it?'"