Once again an isolated extremist event -- the hijacking -- appears to have derailed steps toward peace in the Middle East. But the recent initiatives of Jordan's King Hussein and Yasser Arafat of the PLO and of Israeli Prime Minister Shimon Peres could yet be revived.

American officials surprised Arab leaders last summer with the message that Washington would not lift a finger to expedite an Arab-Israeli settlement until the parties took their own initiatives. This was precisely the message the Arabs needed to hear.

So now, despite the hijacking, we have a situation where Arab leaders, including Hussein speaking for Arafat, have publicly proposed ways for launching direct peace negotiations with Israel -- proposals some of us were told of privately three and four years ago. The talk is not about whether or when there should be negotiations but rather their form.

King Hussein said in Washington recently that he and Arafat agreed negotiations must be carried out in the context of non-belligerency. There is an acceptance by most Palestinians of the formula of "some land for peace." At long last, most of the Arab world has moved away from the practice of holding one opinion in public and another in private on the Palestinian issue.

In Israel, sources close to Peres report he is prepared in principle to enter direct negotiations with Syria regarding the Golan Heights. His five-stage peace proposal for talks between Israel and a Jordanian- Palestinian delegation added to the momentum. Defense Minister Yitzhak Rabin stated in Washington that Israel was ready to accept Palestinians from the West Bank and Gaza "or any other Palestinians who are not members of the PLO" -- an important statement.

President Reagan's 1982 Mideast peace proposals were based on a sense of urgent need to halt Soviet threats to the region. Today the major concerns are Islamic fundamentalism and unbridled terrorism. Containment of religious fanaticism has become for many Arab leaders the motivating factor for pursuing negotiations with Israel.

Hussein, who cannot afford to be seen as making a separate deal with Israel, has called for an "international umbrella" for the talks. It is wishful thinking to believe that the Soviet Union would become involved in any process to which Syria was not a party. Reagan's 1982 proposal did not even mention "Syria" or "Golan Heights." Only in April did a Reagan official reopen exploration of peace with the Syrians, whose final answer has not been given. But in the hijacking, the administration has approached the Syrians, and entered informal discussions with the Soviets, for help in freeing the hostages.

Hussein, Arafat and other Arab leaders do not wish to straitjacket new negotiations by imposing a Camp David framework. Camp David is history. Its achievements must be preserved, but even its most ardent Israeli supporters have been disappointed by the state of the peace with Egypt.

President Reagan can show his country's resolve in the face of terrorism in the Middle East by publicly addressing the peace initiatives made by Peres, Hussein and Arafat. The United States should offer a preliminary hearing to a Jordanian/Palestinian delegation whose members accept direct negotiations with Israel. The United States should also take a quietly forceful position of exploring with Israel and Syria the latter's involvement as a full partner.

The United States should open a new round of regional consultations with the Soviets and encourage them to restore diplomatic relations with Israel and to talk about their vision of a settlement and about how to bring the region more stability, which the Soviet Union claims it favors. Hussein told American lawmakers it was essential to engage Moscow in some way to neutralize its opposition to a peace process. Arafat argues that the Soviets could give a process legitimacy and make a settlement more palatable to a wider array of Arab and Third World states.

It is Hussein, Arafat, Assad and Peres who can make things happen in the Middle East. A year ago we asked the parties to take initiatives. They did. It is now our responsibility to support them. Major military retaliatory strikes after the hostages are released will bury the recent peace initiatives in the rubble. The better course is to focus American political, economic and moral strength on the peace proposals. This would show the right kind of American resolve.