Washington ? President Bush vowed Monday to stay the course in Iraq despite a Shiite Muslim militia uprising Sunday against the American-led occupation that killed seven U.S. soldiers.

Bush said the uprising and the mutilation of four American civilians by an Iraqi mob last week in Fallujah wouldn’t affect the June 30 deadline for transferring power from the Coalition Provisional Authority to Iraqi self-rule.

“We’ve got to stay the course, and we will stay the course,” the president said in Charlotte, N.C., where he was campaigning. “The message to Iraqi citizens is, they don’t have to fear that America will turn and run. If they think that we’re not sincere about staying the course, many people will not continue to take … the risk toward freedom and democracy.”

Staying the course, however, could require an escalating American commitment to Iraq just as the presidential campaign is gathering steam. Opposition to the U.S.-led occupation is spreading from Sunni Muslim Saddam Hussein diehards and their foreign allies to radical members of the country’s Shiite majority, and on Monday, a U.S. military official publicly raised for the first time the possibility that more American troops may be needed in Iraq if violent protests continue to spread.

More important, Sunday’s insurrection pitted U.S. soldiers against the Iraqis who the advocates of invading Iraq in the Pentagon and Vice President Dick Cheney’s office thought would be America’s allies: Shiite opponents of Saddam’s regime. That will make it harder for the administration to defend the guerrilla war in Iraq as part of the war on terrorism, just as a new poll Monday suggested that the war is eroding Bush’s approval rating.

Bush and other administration officials repeatedly blamed Sunday’s uprising by thousands of Shiites on one man: Muqtada al Sadr, a 31-year-old Shiite cleric who urged his followers Sunday to “terrorize your enemy.”

“This is one person who is deciding that rather than allow democracy to flourish, he’s going to exercise force,” the president said. “And we can’t let that stand.”

Experts questioned the administration’s grasp of the situation.

“It’s a lot more serious than the Bush administration is letting on,” said Shibley Telhami, an analyst at the Brookings Institution, a center-left policy-research center. He returned last week from the Middle East. “At first we were told the opposition was Saddam loyalists, then it became the Sunnis in general, now we’re told it’s only one leader of the Shia. They are not coming to grips with the greater realities of the opposition in Iraq. It’s far more widespread than the administration is letting on.”

Radical Shiite militiamen shout from the top of the governor's house they occupy in the southern city of Basra, Iraq. About 150 men took over the building in Monday's invasion in protest over coalition actions against radical Shiite Muslim cleric Muqtada al Sadr, seen in poster.

‘Courting disaster’

Sen. John Kerry, the Democratic presidential candidate, criticized Bush’s unilateral approach to Iraq and foreign policy, saying, “They’re courting disaster. … There’s very little in what they’ve done so far that in my judgment does what’s necessary to minimize long-term risks.”

Decrying the spreading instability in Iraq, Kerry said in Washington: “We can’t allow this to continue. There has to be a political and diplomatic solution, which, regrettably, this administration seems stubbornly determined to avoid.”

Kerry renewed his call for more international involvement and challenged Bush to outline his plans. “I think the president owes it to the American people to explain who we’re turning over sovereignty to and how June 30th, and what is the security plan for after June 30th?”

Asked whether he would support sending more American troops to Iraq, Kerry said he would do “whatever’s necessary to protect our troops that are there and to provide for stability and success, but my preference by far” is more international cooperation.

No way out?

Some senior U.S. officials now say that with both Sunnis and Shiites rebelling against the occupation, they see no way out of Iraq, no way the United States can oversee a smooth transition to Iraqi democratic rule in the foreseeable future and little chance that U.S. forces in Iraq can restore security without more troops.

“The last thing you want in the months before the (American presidential) election is escalation,” said one senior official, who spoke on the condition of anonymity because his remarks were unauthorized and pessimistic. “But seeing Iraq descend into civil war probably would be even worse.”

Bush may be sticking to the June 30 deadline for turning authority over Iraqi “sovereignty” to an as-yet-unidentified governing body, but administration officials have given strong hints that the transfer will mean very little in terms of U.S. involvement.

“There’s not going to be any difference in our military posture on July 1st from what it is on June 30th, except that we will be there then at invitation of a sovereign Iraqi government, which I am quite sure will want us to stay there until killers like the ones who perpetrated these atrocities in Fallujah are brought under control,” Deputy Defense Secretary Paul Wolfowitz said Friday on Capitol Hill.

While preparing for the June 30 transfer, the administration also appears to be bracing for the worst in the aftermath of the Shiite demonstrations. While refusing to call the Shiite action an uprising, a senior official at U.S. Central Command in Florida said American military officials were reviewing what additional forces would be needed if the violent protests spread.

“We do that as a matter of planning, as we would do in any significant event that occurred in Iraq or Afghanistan or anyplace else,” said the official, who spoke on condition of anonymity.

Bush approval dropping

The spate of recent violence is making the American people question anew Bush’s handling of the war. A poll released Monday by the Pew Research Center for the People and the Press showed that the war is eating away at the president’s approval rating, which has dropped from 55 percent last September to 43 percent this month. His disapproval rating grew from 36 percent to 47 during the same period.

Fifty percent of those surveyed said they wanted to keep troops in Iraq, down from 64 percent last September. Those who want to bring American troops home rose from 32 percent to 44 percent.

Public anxiety over the war has prompted Democrats to escalate their attacks on the president. Sen. Edward Kennedy, D-Mass., on Monday called Iraq “George Bush’s Vietnam.”