ENDING THE WAR IN NICARAGUA. US and Latin neighbors float own plans for peace. Congress wonders if the US proposal is a serious one, or if it is just a ploy for more contra aid

The plan for peace in Central America put forward by President Reagan yesterday is being greeted in Congress with a mixture of hope and skepticism. The hope is that the United States is serious about negotiating with Nicaragua - moving that country toward free elections and the region toward stability.

Many in Congress, especially Democrats, have reacted warily to the plan, which calls for a cease-fire between the Sandinistas and the contras followed by a cutoff of US and Soviet aid and the restoration of civil rights in Nicaragua.

The concern is that the proposal is not realistic, that the negotiations will fail, and that President Reagan will have Congress's back up against the wall and be in a good position to get more aid to the contras.

The initiative calls for an immediate cease-fire between the Nicaraguan government and the contra rebels opposing it, followed by the suspension of US assistance to the contras and Soviet-bloc military assistance to the ruling Sandinistas. Under the plan, the Nicaraguan regime would have 60 days to restore civil liberties, establish an electoral commission, and set a timetable for free elections.

``I urge other nations of the world to join in support of this effort,'' Mr. Reagan said, ``and refrain from activities that would jeopardize it.''

Meanwhile, the US and the five Central American countries (Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua) would, for the first time, negotiate toward the ``restoration of the regional military balance'' and the withdrawal of foreign military support and personnel from the region.

``What we are going to work for is success,'' said Secretary of State George Shultz.

But under the terms of the plan, negotiations would have to be completed by Sept. 30, when the current $100 million in military and humanitarian aid to the contras runs out. Otherwise, Congress will vote on the President's 18-month, $150 million contra aid request - larger than any previous contra grant Congress has considered.

Although the President's request faces stiff congressional opposition at present, it is expected that some opposition would dissolve in the event that the negotiations collapsed. If this were to happen, says Sen. Dale Bumpers (D) of Arkansas, ``the President would have an excellent chance of getting his contra aid.''

That admixture of the carrot-and-the-stick, of the promise of diplomacy and the threat of escalated violence in Nicaragua, has caught supporters and opponents of the contras off guard. The initiative has received a good dose of bipartisan praise.

``It could be a very positive thing,'' says Sen. Tom Harkin (D) of Iowa. Says Senate minority leader Robert Dole (R) of Kansas: ``The President is sincere. He's committed to seeing if an acceptable peace is available.''

Many Democrats, however, have reacted warily to the plan. They worry that the plan sets negotiating goals that will be difficult or impossible to meet on the timetable specified by the plan. As a result, they suspect, the plan is designed to fail and to ensure that Congress agrees to a fresh infusion of contra aid.

Some Republican conservatives cringe at the thought of suspending contra aid before the Nicaraguan government agrees to reforms. Similarly, they argue that the plan should be linked to guarantees of new contra aid in the event that talks collapse.

Nevertheless, the initiative has many of the earmarks of a bipartisan effort and, thus, represents an effort that may be difficult to debunk.

House Speaker Jim Wright (D) of Texas wrote the draft of the plan unveiled yesterday. It resembles a proposal set out in a March letter to President Reagan, spearheaded by Rep. James Slattery (D) of Kansas and signed by 111 Democratic and Republican members of the House which was based on the peace proposal of Costa Rican President Oscar Arias.

The administration embraced the Wright proposal, partly compelled by a desire to move out from under the shadow of the Iran-contra controversy, and partly in an effort to improve the chances that a new contra aid package will pass in the fall.

Democrats inclined to back the proposal insist that there is no linkage between a collapse of negotiations and renewed contra aid. At the same time, Mr. Wright and others insist that the Reagan administration is serious about pursuing a diplomatic solution to the Nicaraguan conflict and is not just ``going through the motions'' of diplomatic activity with the expectation of failure, ``thereby gaining an excuse on which to justify further aid to the contras.''

``I have emphatically and repeatedly received assurances that's not the case,'' says Wright. ``This is an all-out, earnest effort to bring peace.''

Earnest or no, many Democrats worry that this plan could provide the political ``cover'' that some members might need to vote for contra aid.

``There are going to be some people who won't vote for the contras for moral reasons, no matter what happens to the negotiations,'' says Representative Slattery. ``But it could paint a few others into a corner.''

That is just what the White House has in mind, some in Congress suspect. ``Trust in the administration's motives is about nil up here,'' says one top Democratic staff member.

The proposal is to be presented at a meeting today and tomorrow in Guatemala City between the heads of state of the Central American nations. Contra aid opponents are particularly concerned about the reaction of Nicaragua's leader, Daniel Ortega Saavedra, to the plan.

But longtime Nicaragua-watchers hesitate to predict in what direction the Sandinista leaders will go. ``I'd hate to bank everything on Ortega's rationality,'' says David Cohen, an anticontra lobbyist.

Peace plan contains far-reaching conditions

Major features of Reagan administration's tentative Central American peace plan:

A cease-fire in Nicaragua, to be negotiated as soon as possible and subject to verification by the Organization of American states or an international observer group.

Once a cease-fire is in effect, suspension of all US military aid to the contras. At the same time, the Sandinista government of Nicaragua would stop receiving aid from Communist bloc nations.

Restoration of civil rights by the Nicaraguan government and setting up of an independent commission to organize free elections within 60 days.

National reconciliation and dialogue among Nicaraguans, with amnesty and full political rights for former combatants.

A plan of expanded trade and long-range economic help for the democratic states of Central America, including Nicaragua.

Withdrawal of foreign military personnel and advisers from Nicaragua and its immediate neighbors, to be negotiated by the countries of the region.

Lifting of the US trade embargo against Nicaragua. That country also would become eligible for American economic aid.

Should no progress be made toward agreement by Sept. 30, when the current $100 million aid program for the contras runs out, the White House plans to ask Congress to approve additional military aid to rebels.

Chronology of US-Sandinista negotiations

November 1980: After Reagan's election, Sandinistas say they want ``friendly'' relations with the United States.

Oct. 30, 1981: US reports that it made a number of proposals to Nicaragua in September, but there had been no response.

Dec. 2, 1981: Secretary of State Alexander Haig and Foreign Minister Miguel D'Escoto meet.

April 8, 1982: US offers Nicaragua an eight-point peace plan.

April 14, 1982: Nicaragua presents US with a procedural response. No time or place is established for negotiations.

June 11, 1983: Special US envoy Richard Stone meets with President Daniel Ortega Saavedra and Foreign Minister D'Escoto.

June 18, 1983: The Nicaraguan ambassador to the US says Reagan responded constructively to a proposal for high-level talks between the two governments.

June 1, 1984: US and Nicaragua begin nine rounds of talks in Manzanillo, Mexico, on normalizing relations.

January 1985: US suspends the talks, citing what it says is Nicaragua's apparent lack of interest in serious discussions.

April 22, 1985: Nicaragua calls for US to halt contras' activity and resume talks with Managua. US rejects Nicaraguan request.

April 23, 1985: In a letter to the Senate, Reagan says he intends ``to resume bilateral talks with the government of Nicaragua.''

June 1985: Reagan repeats pledge but with strong qualifiers.

July 26, 1985: Secretary of State George Shultz rejects a request from Contadora-group members Mexico, Panama, Colombia, and Venezuela that US resume negotiations with Nicaragua. Shultz says the time is not ripe for talks with Nicaragua, mainly because the Sandinistas have spurned invitations to a ``national reconciliation'' dialogue with the contras under the aegis of the Roman Catholic Church. Shultz accuses Nicaragua of having used talks with US ``to undermine the Contadora process.''

Nov. 2, 1985: Nicaragua and US fail, after two rounds of talks, to reach agreement on resumption of negotiations.

Jan. 10, 1986: Ortega asks Contadora group to take concrete actions to bring about resumption of talks between Nicaragua and US.

Feb. 22, 1986: Ortega says Nicaragua is ready to negotiate security concerns with US but will not discuss domestic policy shift.