WASHINGTON — President Bush, trying to defy a history of failure in Middle East peacemaking, is about to embark on his first major trip to the long-troubled region, facing doubts about the seriousness of his commitment and his chances for success.

In the seven years of his presidency, Bush has avoided becoming directly involved in the negotiating process. Disdainful of the process-driven, incremental diplomacy of previous administrations, Bush set sweeping goals — establishment of a Palestinian state and the spread of democracy in the Mideast — while leading the U.S. into wars in Iraq and Afghanistan. He delegated details to others and rarely stepped foot in the Middle East.

"In the region and in the Arab world, he is seen as having been a spectator," said Bruce Riedel, a Brookings Institution analyst, former CIA officer and adviser to three presidents — including Bush — on Middle East and South Asian issues. "This is probably unfair, but it is a reality."

Added Jon B. Alterman, a Mideast expert at the Center for Strategic and International Studies in Washington: "Most leaders in the region with whom I've spoken seem to consider him both naive and callous, and they'll use the home-court advantage to sensitize him to their perceptions of reality."

Bush will arrive in Israel on Wednesday. It is his first trip as president to a nation that is one of America's dearest allies. He also will stop in the Palestinian-governed West Bank, which he toured in 1998, and make his first visits to Kuwait, Bahrain, the United Arab Emirates and Saudi Arabia. He plans a brief stop to the Red Sea resort of Sharm el-Sheik, Egypt, which he visited in 2003.

There are widespread expectations that Bush will go to Iraq and possibly Lebanon. The White House has not announced any such plans.

Roaming the Middle East, Bush will have to compete for attention with the raging presidential campaign back home. That race underscores the fact that Bush's term is coming to an end and that world leaders will be dealing with a new president in a year.

Bush's primary goals for the trip are to try to build momentum for the troubled peace process and encourage broader Arab-Israeli reconciliation. Only Egypt and Jordan now have peace agreements with Israel. The trip also is intended to reaffirm the U.S. commitment to the region and efforts against terrorism.

Bush, in his weekly radio address Saturday, said he would try to push his campaign for democracy in the Mideast — a movement unpopular with authoritarian rulers in countries such as Saudi Arabia, Egypt, Jordan and the Persian Gulf states.

"At this decisive moment in their history, the people of the Middle East can have confidence in the power of liberty to overcome tyranny and terror," the president said. "And all who step forward in freedom's cause can count on a friend in the United States."

With oil costs soaring and recession fears spreading, the United States has a big financial stake in the region. Flush with money from the surge in oil prices, which have tripled since Bush became president, the Middle East has invested heavily in America.

"Historically, a presidential visit or a visit by a really senior U.S. official actually does matter in terms of getting these countries to keep their investments up, to think harder about any shift away from the dollar, to worry about oil production levels," said Anthony H. Cordesman, former director of intelligence assessment at the Pentagon and now an analyst the Center for Strategic and International Studies.

Iran looms large over Bush's trip.

There is confusion throughout the region about a U.S. intelligence report that backed away from once-ironclad U.S. belief that Tehran is intent on building nuclear bombs. The report, known as the National Intelligence Estimate, concluded that Iran halted its nuclear weapons program four years ago but continues to enrich uranium that could be transferred to a secret weapons program.

Saudi Arabia and other Gulf states, which have majority Sunni Muslim populations, harbor deep suspicions about Shiite Iran's apparent designs to establish itself as a major power and have reacted skeptically to the conclusions of intelligence estimate about Iran.

"There's a lot of misunderstanding about how we do intelligence here," said Stephen Hadley, Bush's national security adviser. He said the president would "talk privately and quietly to indicate that we understand the challenge that Iran represents to the region" and explain that the U.S. commitment is firm.

Bush, in an interview Friday with Arab journalists, said the intelligence analysis should be read as saying that Iran remains a threat to peace.

After rattling the Mideast last year by raising the specter of war with Iran, Bush stressed that he believes the showdown with Iran could be solved diplomatically, although "all options remain on the table."

In an interview with Israeli journalists, Bush said he would press Israeli Prime Minister Ehud Olmert to live up to promises to dismantle outposts illegal under Israel law. "The Israeli government has said that they're going to get rid of unauthorized settlements, and that's what we expect, that's what we've been told." Separately, he told Al-Arabiya, the Saudi-owned satellite television station, "No question the settlement activity is a problem. But there's a mechanism to deal with that."

Bush said he was hopeful that Israel and the Palestinians would reach a peace agreement before he leaves office in a year.

Hadley said Bush could advance peace prospects just by going to the Mideast — an assertion challenged by some experts.

"Everyone is looking at this with a very jaundiced eye because they have not seen the president in the region and nobody does believe that Bush is really committed certainly to the peace process," said Kenneth M. Pollack, a Brookings analyst and former director for Persian Gulf affairs at the National Security Council.