President Bush, who vowed yesterday that Iraq's invasion of Kuwait "will not stand," has ordered U.S. government agencies to begin a secret planning effort aimed at destabilizing and eventually toppling President Saddam Hussein from power, according to informed sources.

Bush initiated the effort over the last several days after a series of meetings at which Director William H. Webster outlined the Central Intelligence Agency's evaluation that Saddam, a ruthless leader bent on making Iraq the "Arab superpower," has already put himself in position to manipulate world oil prices.

In angry public remarks yesterday, Bush refused to discuss specific options, but advised reporters: "Just wait. Watch and learn."

In private, the president and his senior advisers have been told by Webster that Saddam poses a threat that goes beyond the immediate Kuwait crisis and extends to the critical long-term economic interests of the United States, the sources said. The CIA evaluation is that Saddam, flush with newly seized Kuwaiti oil reserves, will become a powerful, intimidating force inside the Organization of Petroleum Exporting Countries, driving up oil prices, fueling inflation and possibly throwing the United States into recession and unmanageable fiscal difficulty.

The CIA declined to comment.

After deciding it is now in the U.S. "national interest" to stop Saddam, Bush authorized planning for what sources said will likely be a multifaceted effort to strangle Iraq's economy, foment discontent in the military and support resistance groups inside and outside the country. Sources said this effort will include covert activity, which could be difficult if not impossible given that Iraq is organized as a police state and Saddam has brutally repressed any internal opposition.

It could not be learned what timetable Bush has set for making decisions about how to actually implement the campaign against Saddam. The president has asked for the broadest possible set of options and plans for dealing with what is being treated as a major challenge to his presidency and his political standing at home, the sources said.

Tense and angry, Bush arrived back in Washington from Camp David just after 3 p.m. yesterday and spoke briefly with reporters before convening a meeting of his national security advisers to review the situation in the Persian Gulf.

Although his rhetoric was not substantially different from the warnings he has issued since Iraq overran Kuwait on Thursday morning, his demeanor was. He appeared tired, ill-tempered and firm, cutting off one reporter with a testy comment: "What's the question? I can read."

Bush was sharply critical of the failure of other Arab leaders to force Iraq to withdraw its troops from Kuwait, especially Jordan's King Hussein, who defended the Iraqi invasion and called President Saddam "a patriot."

"I want to see the Arab states join the rest of the world in condemning this outrage, and doing what they can to get Saddam Hussein out," Bush said. On Jordan's Hussein, he added, "I am disappointed to find any comment by anyone that apologizes or appears to condone what's taking place."

Three days ago, Bush said Arab leaders had requested time to handle the invasion on their own, and at the time he appeared to put some hope in that regional effort. By yesterday, however, his patience appeared to have worn thin.

"I was told by one {Arab} leader that I respect enormously . . . that they needed 48 hours to find what was called an Arab solution," Bush said. "That obviously has failed."

Bush said he was continuing his talks with other world leaders in an effort to bring about a "united front" to "isolate Iraq economically," adding, "There is no intention on the part of any of these countries to accept a puppet government {in Kuwait}, and that signal is going out loud and clear to Iraq."

Asked how the United States and other countries could prevent Saddam from installing a puppet government in Kuwait, Bush replied curtly, "Just wait. Watch and

learn."

The president said he wants the United Nations "to move soon" with economic sanctions against Iraq to reverse what he termed "vicious aggression" against Kuwait. "This will not stand," he said. "This will not stand, this aggression against Kuwait."

Bush refused to discuss military options, especially if the Iraqis move against neighboring Saudi Arabia. But he said "you can assume" he is working to persuade Saudi Arabia and Turkey to shut off Iraqi oil pipelines that run through their countries. He said he was expecting a telephone call from Turkish President Turgut Ozal and that he planned to talk again later in the day with Saudi King Fahd.

"All options are open," Bush said.

Bush was unyielding in his condemnation of Iraq. Asked whether Iraqi troops appeared to be dug in in Kuwait, he replied, "Iraqi lied once again. They said they were going to start moving out today and we have no evidence that they're moving out."

Bush said the NATO countries were in agreement about how to move against Iraq. He said he had talked with Canadian Prime Minister Brian Mulroney and French President Francois Mitterrand and that British Prime Minister Margaret Thatcher would meet with him here today for further discussions.

He also praised Japanese Prime Minister Toshiki Kaifu for his country's decision to "crack down on imports from Iraq."

Bush said he did not believe American lives were in danger in Kuwait but added that "you know how I feel about the protection of American life and the willingness to do whatever is necessary to protect it."

A decision to look for ways to topple Saddam represents a marked turnabout from the administration's previous attitude toward the Iraqi leader. Saddam received explicit U.S. backing during the Iran-Iraq war, including intelligence sharing, increased non-military trade and food shipments and Bell executive helicopters which he converted to military use. This was largely an effort to use Iraq as a strategic counterbalance to Iran and keep the oil flowing.

After the 1988 Iran-Iraq cease-fire, Baghdad's relations with Washington deteriorated dramatically with Saddam's campaign to crush the Kurdish rebellion, whose leaders had sided with Iran. His increasingly bellicose statements, his stockpiling of the Third World's largest chemical weapons arsenal, and his quest for strategic weapons also strained relations with the United States.

But as recently as last week, the administration was still trying to work with Iraq, in part because Saddam had served as what officials thought was a moderating influence in negotiations over a Palestinian role in peace talks with Israel. Assistant Secretary of State John H. Kelly, in testimony to the House Foreign Affairs Committee last Tuesday, said the administration remained opposed to broad economic sanctions on Iraq.

But by taking Kuwait, the Iraqi president now controls nearly a quarter of OPEC's total oil production, second only to Saudi Arabia. U.S. officials fear this and his military might will give Saddam enough sway in the cartel's quota and pricing deliberations to intimidate Saudi Arabia. "If he installs a puppet regime in Kuwait, he will get enormous leverage over the Saudis," said a senior official. "If you allow him to do that, he's achieved his objectives." The Saudis would be "paralyzed," the official added.

Saddam needs higher oil prices to meet his problems at home, including a massive foreign debt, an expansive weapons program and unmet consumer needs. Analysts said they fear that other OPEC members, including ravaged Iran, would be only too happy to see world oil prices rise.

Yet Bush's efforts to oust Saddam could be extraordinarily difficult, as were earlier attempts to overthrow Libya's Moammar Gadhafi. The sources said the most promising immediate avenues appear to be strangling Saddam financially, hoping that without oil exports, additional money and new arms supplies, he would face discontent at home and in the military.

The sources said Bush and his advisers had ruled out any attempt at assassination, which is against the law.

A member of an Iraqi opposition group in London, who asked not to be identified, said that while talks have been held with American officials in the past, none has occurred since the invasion of Kuwait.

The opposition is badly splintered and largely in exile. Tiny exile dissident groups exist in European and U.S. cities, but are reluctant to operate publicly.

The opposition coalesces around two poles: Kurdish nationalism and Islamic fundamentalism.

There are a few groups of fundamentalist Shiite Moslems, the most prominent of which is Dawaa Islamiya (the Islamic Call). During the war with Iran, Dawaa Islamiya received support or shelter from Iran and Syria and claimed responsibility for bombings and assassination attempts against Saddam. Iranian exiles say the group maintains an underground presence of some sort within Iraq, including the military.

Iraq's Kurds, who form an estimated 15 to 20 percent of the population, have long resisted rule from Baghdad. The main Kurdish opposition to Saddam, the Democratic Party of Kurdistan (DPK), was helped by Iran during the war and fought Iraqi troops in the northern Kurdish homeland. But the cease-fire allowed Saddam to crush military opposition by the Kurds and to pursue a campaign to relocate them to other parts of Iraq.

There is also a small Communist Party, which broke with Saddam after he purged its leaders in 1978-79. Since then, the communists have been allied with the DPK and another Kurdish group, but appear to have posed no real threat. Staff writer James Rupert contributed to this report.