In engaging himself again in trying to settle the often intractable conflict, Mr. Bush must address the opposing demands of Arab leaders and of his own political base, which includes evangelical Christians and politically conservative Jews. Supporters of the Palestinians want more pressure on Israel, while many of Mr. Bush's conservative backers do not want him to beat up on Israel as an election approaches.

The delicacy of the domestic — and international — politics was reflected by the almost low-key manner in which the plan, known as the "road map," was released today in the United States.

Instead, administration officials said Mr. Bush wanted the focus to be on presenting the plan to the parties in Jerusalem and in Ramallah, the Palestinian headquarters, not in Washington.

Administration officials said today that their priority would be to avoid further discussions of the plan and to concentrate instead on steps that could be taken on the ground.

"There have to be some steps by the Palestinians and some reciprocation by the Israelis if we are going to restore trust and dialogue on both sides," said an administration official. "We haven't got much time."

When he visits Israel in the second week of May, Secretary of State Colin L. Powell is expected to press the Palestinians to disarm militant groups. He will also try to persuade the Israelis to ease the hardships of Palestinians living under military occupation in the West Bank and Gaza.

These are precisely the steps that the Bush administration has tried to orchestrate before, without success. But three things are different now, American officials say.

First, and most obvious, is rewriting the political landscape in the Middle East, now that American and British troops have crushed Saddam Hussein, Israel's enemy. Americans believe that the victory gives Mr. Bush new leverage throughout the region.

Second is the strategy of the "road map." Drafted by the United States in concert with the European Union, Russia and the United Nations, the plan theoretically presents a united front to prevent the Palestinians, who have closer ties to the other partners, from playing one party against the other.

The third factor lies in the relationship that Mr. Bush now has with Arab countries, which have beseeched him for more than a year to get involved in Middle East peace negotiations. These pleas became more insistent and anguished as the idea of war with Iraq gathered speed over the last six months.

Now administration aides say Mr. Bush is planning to approach these Arab nations. Washington wants Arab leaders to persuade the new Palestinian government to stop supporting militant groups that carry out attacks on Israeli civilians and make it impossible for Israel to make the concessions needed to get the talks going.

Secretary Powell is due to stop in Syria and then Lebanon this week for some candid talk with President Bashar al-Assad. Later in the month he will travel to other Arab countries and to Israel, and will meet with the new Palestinian prime minister, Mahmoud Abbas.

Syria has been warned that it might be the next focus of American pressure after Iraq. Then the administration shifted gears to say that Syria had been cooperating on searching for Iraqi leaders who may have escaped there.

There is a strain of thinking in the administration, and among some experts, that Syria could return to its promising role as a partner in an agreement with Israel, as seemed possible in the 1990's. Indeed today Mr. Powell told a Senate appropriations subcommittee on foreign affairs that he thought Mr. Assad "wants to be a part of that comprehensive solution" in the Middle East.

But no less tough will be the other part of Mr. Powell's Arab diplomacy, with the three Arab countries he is to visit later in the month: Saudi Arabia, Jordan and Egypt.

Since the Arab League supports the Palestinian Authority with hundreds of millions of dollars in subsidies each year, the administration reasons that the leverage of funding might persuade the Palestinians to renounce attacks on Israeli civilians for the good of progress toward a Palestinian state.

But while Mr. Bush has said repeatedly that no progress can occur without a decline, or even an end, to terrorist attacks on Israelis, administration officials acknowledge that no progress can be made without Israel taking steps to build up Mr. Abbas as an alternative to Yasir Arafat.

A year ago, Mr. Powell met with Mr. Arafat in Ramallah while he was surrounded by Israeli forces attacking his headquarters. It was a low moment in American diplomacy, American officials now agree. It led to Mr. Bush's demand that the Palestinians find a new leader.

Mr. Bush hailed both the publication of the peace plan and the selection of Mr. Abbas today, declaring him "a man I can work with." He also called on Israelis, Palestinians, and especially Arab nations in the region to take their own steps to reach that agreement. 

Many conservative groups have criticized both the plan and the philosophy behind it. The most prominent, perhaps, was Representative Tom DeLay, the House majority leader, who called it dangerous to Israel. 

A final choice for Mr. Bush is whether to select a presidential envoy to press the Middle East peace negotiations. On one hand, such a move would demonstrate to the region that he is committed to bringing about a settlement.

But on the other hand, Mr. Bush has openly criticized his predecessor, Bill Clinton, for precisely such involvement and may not want to leave himself vulnerable to the same criticism if the negotiations falter. Administration officials say that the decision is not likely to be made until Mr. Powell returns from the Middle East in mid-May.

Whatever the results of his trip, the issue is not likely to be one Mr. Bush can avoid. There are too many people demanding that he remain involved, whatever the political risk.