WASHINGTON - President Bush's proposal to send 21,500 additional soldiers to Iraq encountered strong, sometimes angry bipartisan opposition on Capitol Hill on Thursday, and his top national security advisers, dispatched to defend the strategy, were greeted with a skepticism not seen from Congress over the past six years.

Lawmakers said they had little confidence that the Iraqi government has the capacity to deliver on promises to take the lead in cracking down on violent militias and providing security in Baghdad, as the president's plan contemplates. Democrats and Republicans alike said they were concerned that Bush's plan, announced Wednesday night in a prime-time nationally televised address, is too little and too late, and does not appear very different than previous efforts to secure the capital.

The administration's emissaries, Secretary of State Condoleezza Rice and Defense Secretary Robert Gates, sought to reassure the lawmakers that the plan could work if they were only given the time. Gates said he detected a much greater determination from Iraq Prime Minister Nouri al-Maliki to go after "all lawbreakers" with "no exceptions." He suggested that the prime minister would confront the militias fueling sectarian violence -- including insurgents controlled by radical Shiite cleric Muqtada al-Sadr.

Still, the ferocity of the congressional condemnation seemed to stun the White House, which had hoped to rebuild an element of bipartisan consensus around Bush's plan. It was further indication that the new Democratic Congress is headed toward a series of potentially epic clashes and floor votes over the conduct and funding of the nearly 4-year-old war.

Congressional skepticism is clearly being fueled by the public: A majority of Americans oppose Bush's decision to send more troops, and about one-third said the plan is likely to make victory there more likely, according to a new Washington Post-ABC News poll.

During Thursday's tense hearings, Rice appeared to be on the receiving end of the toughest grilling, during her appearance before the Senate Foreign Relations Committee. Not a single senator from either party expressed support for the president's plan, many posed hostile questions, and others expressed deep doubt about the whole Bush administration premise of creating a viable democracy in the heart of the Middle East.

Sen. Chuck Hagel, R-Neb., a Vietnam War veteran, called the plan "the most dangerous foreign-policy blunder in this country since Vietnam," and accused the administration of sending U.S. troops into a civil war.

"To ask our young men and women to sacrifice their lives, to be put in the middle of a civil war, is wrong," he said. "It's . . . morally wrong. It's tactically, strategically, militarily wrong."

Sen. Bill Nelson, D-Fla., spoke of the limits of patience. "I have supported you and the administration on the war, and I cannot continue to support the administration's position," he said. "I have not been told the truth. I have not been told the truth over and over again by administration witnesses, and the American people have not been told the truth."

Rice maintained her composure throughout the more than three-hour hearing, conceding to the senators that doubts are warranted but pleading for patience. "I want you to understand that I personally, too, understand and know the skepticism that is felt about Iraq and indeed the pessimism that some feel," Rice said.

Asked by a lawmaker if she had confidence in the Maliki government, Rice said she did, adding, "I think he knows that his government is on borrowed time."

Appearing at Fort Benning, Ga., Bush told cheering soldiers that daily life in Iraq would eventually improve but that his new strategy will not yield immediate results. "The American people have got to understand that suicide bombings won't stop immediately," Bush said. "The IED attacks won't stop immediately."

At an early-morning news conference, Gates said the planned increase in troops is being viewed as a "temporary surge," but added: "No one has a really clear idea of how long that might be."

Gates also announced he was recommending an increase in the size of the Marine Corps and Army by 92,000 soldiers over the next five years while he joined with other administration officials in offering new warnings about the growing power of Iran. He said one consequence of a failed U.S. effort in Iraq would be "an emboldened and strengthened Iran."

The White House is running the risk that the widespread discontent on Capitol Hill could mushroom into an embarrassing resolution disapproving the president's plan or, worse, the imposition of limitations on funding for the war. White House aides said they fully expected criticism from many quarters, but expressed disappointment that many lawmakers do not appear to be giving more than a cursory review of the new strategy.

Still, White House counselor Dan Bartlett expressed optimism that a showdown with Congress over funding could be avoided, despite a vow by some House Democratic leaders to try to derail funding for the additional 21,500 soldiers. "It appears the Democrats are divided on that issue themselves," he said. "We obviously hope it doesn't get to that point -- and my personal opinion is, I don't think it will."
The Chicago Tribune contributed to this report.

Commentary: