The first 11 days of the war have brought back with a vengeance the deep splits that have long existed within the Bush administration and the Republican Party over policy toward Iraq.

Already there is a behind-the-scenes effort by former senior Republican government officials and party leaders to convince President Bush that the advice he has received from Vice President Cheney, Defense Secretary Donald H. Rumsfeld and Deputy Defense Secretary Paul D. Wolfowitz -- a powerful triumvirate frequently at odds with Secretary of State Colin L. Powell -- has been wrong and even dangerous to long-term U.S. national interests.

Citing past public statements by Cheney and others about the prospective ease with which the Iraq war could be won and the warm welcome U.S. forces would receive from the Iraqi people, one former GOP appointee said he and his allies were looking at "whether this president has learned something from this bum advice he has been getting."

Other Republicans and Bush administration officials, some close to Powell, also expressed concern that the Iraq war plan, with its "rolling start" using a relatively small force, was based on faulty assumptions that the Iraqi government would quickly collapse. Moreover, there is fear among some officials, especially in the State Department, that postwar diplomacy, if handled poorly, could result in further U.S. estrangement from allies and international institutions.

Bush, who appears to value tension among his top advisers, "has been very Delphic on this and hard to read" on the emerging internal debate, a Bush adviser said.

Powell has stressed his support for the war plan, and those operating behind the scenes said they were acting without Powell's blessing. Indeed, among this group, there is criticism of Powell for failing to combat some of the assumptions about the war with Iraq more forcefully. "Powell won't pick up the fight and won't represent State Department professionals who are appalled by what is about to happen," a former party official said.

Administration officials are generally close-mouthed about their discussions and officially insist there is unity among Bush's senior national security advisers. But they also acknowledge that within this administration disputes among senior Cabinet officials are never really settled. With war now under way, the stakes in the debate over Iraq are much higher, affecting not only the course of the conflict but the world's acceptance of the U.S. invasion and its aftermath.

Officials dismissed complaints about the war's progress as premature. They said that Bush's entire national security team agreed to the plan, which in little over a week has resulted in control over nearly half the country, troops 50 miles from Baghdad and the initial delivery of humanitarian supplies. On Saturday during a teleconference with his senior advisers, the president endorsed Rumsfeld's desire to prepare for an advance on the Republican Guard around Baghdad.

"The president has demonstrated strong leadership and has the unified support of his whole team," a senior defense official said. "My concern about this sort of gossip is that it is very important to maintain the unity of this effort. It is not a time to get weak in the knees." The Iraqi government, the official added, will grab at "every little straw," and thus any suggestion of division in the top levels of the administration "plays into the hands of Baghdad's propaganda." A spokeswoman for Cheney declined to comment.

Powell distanced himself from those questioning the war plan and the administration's unity. "I was briefed regularly on the plan as it was developed," he said yesterday. "I have full confidence in the plan and in the commanders executing it."

A subtext of the debate, expressed by people sympathetic to Powell, is the notion that the secretary of state more closely reflects the internationalism of President George H.W. Bush, who 12 years ago assembled a broad military coalition -- and a force of nearly 500,000 American military personnel -- to oust Iraq from Kuwait. Indeed, the former president, in an interview published this week in Newsweek, twice defended Powell without prompting. "I hate criticism of Colin Powell from any quarter," he said. Some former and current officials viewed the remarks as a message to Powell's opponents within the administration.

"The only one who can reach the president is his father," one former senior official said. "But it is not timely yet to talk to him."

Some within the group of former GOP officials were advocates last summer of going to the United Nations to win broader international support for confronting Iraq rather than moving unilaterally. The president decided to try to obtain U.N. backing -- a course Powell strongly favored -- after his father's national security adviser, Brent Scowcroft, and secretary of state, James A. Baker III, went public supporting that approach. Administration officials, however, said that Bush always intended to go to the United Nations and was not influenced by his father's former aides.

Since that time, Scowcroft, who currently heads the president's Foreign Intelligence Advisory Board, has had limited access to the White House because of his public criticisms of the administration's policies toward Europe, NATO and the United Nations.

Appearing yesterday on ABC's "This Week," Baker defended the administration's conduct of the war. But in the aftermath, he said, Bush should call an Arab-Israeli peace conference, much as his father did in 1991, and insist on implementation of the "road map" to peace -- drafted by the United States, the European Union, Russia and the United Nations -- without putting prior conditions on either side. Some have accused the current administration of putting too much of the initial burden for progress on the Palestinians.

"There's clearly a view that the conduct of foreign policy in a multilateral context, led by the United States, has been de-emphasized, and that this isn't a good way to go about doing things," said one person familiar with the argument made by the former GOP officials. "There are fissures in the administration on the bigger point of what kind of diplomacy are we going to be conducting and how does our military force need to be shaped to respond to that foreign policy."

Powell is regarded by his adversaries in the administration as a skilled bureaucratic infighter who somehow appears to emerge unscathed even when he doesn't achieve diplomatic success -- a quality they attribute to manipulation of the media and careful attention to his public image. In interviews, Powell twice last week cited his Gallup poll ratings. "The American people think I was doing a good job by, oh, 83 percent," Powell said.

Powell's high public standing has led some of the secretary of state's skeptics to wonder darkly why people don't blame the nation's top diplomat when diplomacy fails, yet claim the war would be going better if only the president had listened to the top diplomat.

Within the administration, Powell retains close contact with the uniformed military, who often are in conflict with Rumsfeld. Many top officials suspect, though they don't have evidence, that Powell wields influence through this back channel. There is "grumbling among the generals toward the White House" over the direction of the war, a source said.

The president has, at various times, backed both sides of the debate, agreeing with Powell on the need to try to seek broad international support and Rumsfeld on military strategy. Last week, in an interview with National Public Radio, Powell dismissed suggestions that his advice has been ignored. "Personally, I'm very much in sync with the president, and he values my services," he said.

"Rumsfeld wants to put the 'Powell Doctrine' into obsolescence," the Bush adviser said, referring to the military strategy outlined by Powell when he was chairman of the Joint Chiefs of Staff. In its broadest sense, the doctrine -- which guided Pentagon thinking during the Gulf War 12 years ago -- calls for decisive force, clear goals and popular support to ensure success.

Rumsfeld wants to retire the Powell Doctrine "first because he truly believes that the new military with the new technology needs to fight different kinds of wars," the adviser said. "Secondly, he sees new kinds of foreign policy challenges, and he ultimately wants to run foreign policy, not just the Defense Department. Those foreign policy challenges require the U.S. to be able to deploy force quickly and with dramatic positive effect in multiple places at multiple times because you're battling these non-state actors."

Occasionally, the fault lines change. In the run-up to the war, sources said, the State Department and the vice president's office pressed the Pentagon to send ships carrying tanks and equipment for the Army's 4th Infantry Division to Kuwait immediately after Turkey rejected a request on March 1 to accept them. But the Pentagon wanted to keep trying to open a northern front through Turkey and won the argument. The ships began to move only last week.

Powell asked whether it is was a problem to not have the 4th Infantry in place before the war started, a source said, and was assured it was not. Powell said in a recent interview that he offered his advice on the war plan, which originally envisioned an even smaller force than the one that headed into Iraq 10 days ago. "I think I have made useful contributions, appropriate to my experience but also appropriate to my current position," he said, adding, "I keep in my own lane."

When Bush on the eve of war pointedly asked each of his senior advisors if they had any problems with the war plan, Powell raised no objection. A senior State Department official said Powell did not recommend a larger force.

Indeed, Powell has publicly denied that the war plan fails to live up to the Powell Doctrine. He also has expressed repeated confidence in the progress of the war. Assertions that the force isn't big enough are "nonsense," Powell told CBS last week. "It's the usual chatter."

Yet, in a series of interviews since the war started, Powell distanced himself from the confident assurances of imminent victory expressed by other senior officials and offered his interpretation of the military campaign. The day that Lt. Gen. William S. Wallace, the senior Army officer in Iraq, was quoted as saying U.S. forces had faced unexpected problems -- remarks that infuriated White House officials -- Powell said: "I have absolute confidence in the commanders who are running this war. . . . And I know it. I trained them."

Powell also made a comment that was widely interpreted in official Washington as a jab at Wolfowitz, a frequent nemesis who did not serve in the military.

"When war comes, that's [casualties] the price that has to be paid," Powell said on NPR. "And it's paid not by intellectuals but by wonderful young Americans who serve their country and believe in the cause for which they are serving."

After checking with Powell, the senior State Department official said the comment "wasn't directed at anybody; it's just a statement of truth."

Staff writer Mike Allen contributed to this report.

Defense Secretary Donald H. Rumsfeld, left, talks to Vice President Cheney and President Bush outside the White House on March 19 soon after Bush authorized Operation Iraqi Freedom.Secretary Powell, shown at a news conference March 17, says he has full confidence in the commanders of the war in Iraq and in the war plan.