Peace plan still viable, say experts, but does Reagan have the will?

A year ago to this day, in the midst of much fanfare, President Reagan announced a sweeping new Middle East peace plan. Today, amid new fighting in Lebanon, the Reagan plan appears to be almost forgotten.

Can the President's plan be revived?

Yes, say some Middle East specialists, but only through enormous effort and political risk-taking unlikely to be undertaken in an American election year.

For the moment, the Reagan administration is largely on the defensive, reacting to Mideast events - helping to put out fires.

In the view of some specialists, a revival of the Reagan plan would almost certainly create new tensions with Israel, which harshly rejected the plan at the outset.

But those who advocate a revival of the plan point out that it had gained widespread support in the United States, and that this included support from Democrats and from many members of the influential American Jewish community. Arab diplomats say that the cost of not reviving a comprehensive peace plan will be a ''distancing'' of key Arab nations from the US. But Arab leaders question whether the Reagan administration has the political will to compel Israel to accept American proposals for an Arab-Israeli peace.

New doubts about the administration's political will were raised early last month when the US vetoed a United Nations Security Council resolution calling for the dismantling of Israeli settlements on the West Bank of the Jordan River. President Reagan later tried to dispel those doubts by stating in his regular Saturday radio address, on Aug. 27, that the settlements were an obstacle to peace. At the same time, the administration opposes the dismantling of existing settlements.

In his radio address, the President stated that his year-old peace initiative ''definitely is alive.'' The administration has been reshuffling its Middle East team at the State Department, leaving some uncertainty as to how it will proceed. Nicholas A. Veliotes has been replaced as assistant secretary of state for Near Eastern affairs by Richard Murphy, ambassador to Saudi Arabia.

Administration officials defend the Reagan plan, now regarded by some specialists as moribund, by arguing that it brought several of the parties to the Arab-Israeli conflict close to agreement, and that it continues to stimulate thinking in the region about how to achieve peace. Key Arab nations were brought to the point of deciding not whether they should make peace with Israel, but how they should make peace, one official said.

The Reagan peace plan proposes self-government for the Palestinians of the West Bank and Gaza in an entity to be linked with the Kingdom of Jordan. King Hussein of Jordan tentatively endorsed this idea, but backed away after failing to gain approval from the Palestine Liberation Organization (PLO).

Some specialists, such as Sol Linowitz, chief Middle East negotiator under the Carter administration, say it was a mistake to ever make the plan depend on acceptance by Hussein and the PLO.

Ambassador Linowitz says that the US must now encourage Egypt and Israel to return to the negotiating table, and to resume their talks over Palestinian autonomy. The Egyptians broke off the autonomy talks with the Israelis after the Israelis invaded Lebanon. Linowitz also says that even as it copes with the Lebanon conflict, the US must also resume its own direct talks with the Israelis on the Palestinian question.

''It was a great mistake to allow the Egyptian-Israeli talks to be derailed, '' said Linowitz. ''And it was a great mistake not to follow up with Begin on the Reagan plan, to show that we seriously intended to move forward and expected his cooperation.''

Linowitz said that Begin initially rejected the Reagan plan because Reagan announced it even before discussing it with Begin.

''But three or four weeks later, after he'd calmed down, Begin expected a follow-up from us,'' Linowitz said.

If the US now waits, in the wake of Begin's resignation, until the Israelis sort out their political turmoil, it will be making another mistake, Linowitz said.

He adds that a special envoy should be appointed to deal with the peace plan alone and should not be expected to deal both with the plan and with Lebanon, as envoy Philip C. Habib was expected to do.

Some specialists now believe that negotiations with the Israelis over the status of the West Bank might be made easier by the departure of Prime Minister Begin. Begin said he believed that Israel had a religious and historical right to the West Bank and instituted what looked like a policy of creeping annexation of that territory. But while Begin's ultimate successor might prove to be a more pragmatic and flexible politician than Begin, a successor might also be in a weaker political position than was the popular Begin, thus making him even less likely than Begin to compromise on this sensitive issue.

Two Americans who have grappled with the problem at a high level, former Secretary of State Henry Kissinger and former Assistant Secretary of State Harold Saunders, have said in separate interviews recently that the United States cannot accept the annexation of the West Bank and that this places the US and Israel on divergent courses.

But administration officials say there is little they can do to stop Israel's West Bank settlements as long as the Arabs are unwilling to negotiate with the Israelis and a majority of Israelis fail to oppose the settlements. Ambassador Linowitz argues, however, that the Israelis could be persuaded to place a limit on the number of settlements they would build.

The settlements issue seems to bother some Arab diplomats more than anything else. In their view, it dramatizes the Americans' inability to curb Israeli expansionism. And, as they see it, continued settlement activity closes out the option of an exchange of territory for peace, an option which has always been a part of American peace plans, including the Reagan plan.

''A large measure of US credibility revolves around the question of settlements,'' said Clovis Maksoud, the Arab League's permanent observer at the United Nations and special envoy to the United States. ''If the Arab world realizes that we are coming close to the point where Israel preempts any political base for Palestinian self-determination, we will have to reassess all of our positions.''

''Grave doubts emerge when, because of side agreements between the US and Israel, every negotiated arrangement which is brokered by the Americans is stonewalled by the Israelis,'' said Maksoud in an interview. ''There are times when Israel has to be penalized.'' ONE YEAR UNDER THE REAGAN PLAN PLO evacuates Beirut, August-September 1982 Palestinian civilians massacred in Beirut refugee camp by Lebanese militiamen, September 1982 PLO refuses to let Jordan's King Hussein enter US-sponsored peace talks, April 1983 Fighting breaks out between factions of Arafat's Fatah guerrilla group in eastern Lebanon, May 1983 Israel approves 10 new West Bank settlements on Sept. 5, 1982 Israel's Prime Minister Begin rejects Reagan plan, Sept. 2, 1982 US Marines arrive in Beirut Aug. 25, 1982; leave Sept. 10, 1982; return in force Sept. 29, 1982