For more than nine months Jordan's King Hussein has tried to forge ahead in his joint peace initiative with the Palestine Liberation Organization despite the sometimes erratic behavior of his PLO partners and threats from Syria. The plan also faces the roadblocks of Israel's apparent preoccupation with its own economic and political troubles and the virtual immobility of the United States.

Now, added to his problem, in the view of analysts here, is the public skepticism and reticence of his closest allies in the Arab world gathered at a special summit meeting held here this week.

Neither of the most radical Arab states -- Syria or Libya -- attended. But after three days of what participants said was passionate debate, those Arab leaders who did come were able to offer Hussein nothing better than a statement that they had listened to him and PLO Chairman Yasser Arafat and that they hoped anything these two did would be in line with an Arab peace plan unanimously approved at the 1982 summit in Fez, Morocco.

That plan virtually dropped from sight in 1983 after gaining little support outside the Arab world.

If Hussein and Arafat had hoped for a little blocking from their friends, what they got instead was the message that, "You've got the ball, you run with it, and we'll sit back and see if you break any rules."

Hussein, whose nation could ill afford the kind of isolation in the Arab world Egypt suffered after signing the Camp David accords, carefully has tried to build wider Arab support for the plan ever since he proposed its outline in November 1984.

Both he and Arafat, who signed a joint action plan in February for peace with Israel, have traveled extensively in the region to explain it to other leaders and attempt to gain their blessing.

Why such reticence at the summit? The explanation given today at a press conference by King Hassan II of Morocco, the host of the meeting, was that despite hopes raised by the Jordanian-PLO plan, it has yet to show concrete results.

Other Arab officials, making the same point yesterday, blamed the United States for not meeting with a joint delegation of Jordanian and PLO-appointed officials whose names were submitted to Washington a month ago.

But Washington has been slow to move partly because it does not want to get out too far ahead of Israel in this process. U.S. officials insist that their objective is to facilitate direct talks between Israel and a Jordanian-Palestinian delegation. There is no sense, they say, in meeting with people Israel will not talk to.

As a result, direct contact with the PLO still is ruled out by Washington while the Arab League members represented at the summit meeting here reiterated strongly in their communique that the PLO is the only legitimate representative of the Palestinians.

The more moderate Arab leaders have tried to show that they are willing to talk as long as certain fundamental questions are addressed.

Morocco's King Hassan, who is president of the Arab League, said today that he would invite Israeli leaders here to discuss any peace plan they might offer that would return the occupied territories and recognize the right of the Palestinian people to self-determination.

But Israel, with a coalition government facing a desperately shaky economy and growing anger over attacks on Jewish settlers in the West Bank, has shown little interest in exerting major new efforts to find a diplomatic breakthrough.

Instead, public debate there recently has focused on whether to attack Palestinian bases in Jordan. Originally suggested by Ariel Sharon, a Cabinet member from the right-wing Likud bloc and architect of the Lebanon invasion, the idea was dismissed by Prime Minister Shimon Peres of the Labor Party.

Nevertheless, Hassan warned sharply here today that "if Israel does this, it will be the greatest folly. Jordan is a responsible country and has friends in the world who won't permit it to be hurt."

Another element that weighed strongly against an endorsement of the Jordanian-PLO plan by the summit here was Syria's opposition.

While about half of the 21 Arab League members were represented by their leaders, some -- among them Saudi Arabia, Iraq and Sudan -- sent lower ranking officials. But Syria, which strongly opposed the convening of the summit, boycotted it, along with Libya, Algeria, South Yemen and Lebanon.

Most of those who attended, however, seemed to feel Syria's presence almost as strongly as if it had come.

Hassan said in his opening remarks Wednesday that he hoped those countries that did not attend were here "in spirit if not in the flesh." In several ways they were.

Syria argues that there can be no settlement with Israel until there is a strategic balance that forces it to give up the occupied territories in exchange for peace. Several delegation members privately expressed sympathy with this view.

But even those who disagree with Syria appeared clearly aware of its ability to retaliate against those who oppose it. Few Arab leaders are willing to risk the wrath of Syrian President Hafez Assad by openly endorsing measures that directly oppose his central policy.

In this context of combining inaction by his friends and intimidation by his enemies, Hussein reportedly has decided to take a brief vacation, waiting to see if one side or another can give him and the joint initiative the breaks they need.