The nation's top military officer yesterday gave a strongly optimistic assessment of the military, political and economic situation in Iraq, citing "great progress on all fronts" there.

"It's going to be tough, but, no, I don't think we're on the brink of failure" in Iraq, as some have asserted recently, said Air Force Gen. Richard B. Myers, the chairman of the Joint Chiefs of Staff. Rather, he told the House Armed Services Committee yesterday, "I think we're on the brink of success."

The latest in a series of congressional hearings on the Bush administration's handling of Iraq was marked by partisan sniping. Political squabbling is unusual in Armed Services Committee hearings, and it indicates how divided Congress is becoming over the U.S. situation in Iraq. Rep. Duncan Hunter (R-Calif.), the committee chairman, engaged in an extended argument with Democratic Rep. Kendrick Meek, a freshman from Florida, over whether the committee was paying sufficient attention to the torture of Iraqi detainees by U.S. soldiers.

Hunter, who has been critical of the Senate for focusing on the abuse situation, told Meek, "I don't know where you were, but we've had more hearings, open and closed, on this one subject than any other issue that has been before this committee."

Meek replied, "I'm sorry for trying to be a congressman asking questions that may not necessarily be welcomed."

But the day's hearing was dominated by Myers's upbeat account of trends in Iraq, which contrasted somewhat with the previous Capitol Hill appearance of a senior Pentagon official. When Deputy Defense Secretary Paul D. Wolfowitz testified earlier this week, he conceded that several major miscalculations had marred the U.S. occupation effort over the past year.

Myers accentuated the positive, usually in fairly vague terms. Talking about the restoration of power, water and sanitation services, he said: "There's lots of that kind of thing that is going on in the country that I think give us great, great hope."

The general especially expressed great expectations of Iraqi support for the planned turnover of limited authority to an interim Iraqi government at the end of next month. "I think there is reason for great hope that the Iraqi people will take this and run with it," he said.

Some Iraqis, defense experts and members of the committee have said they are deeply concerned by the political situation in Iraq, with the assassination this week of the Iraqi Governing Council president, the lack of clarity about who actually will be running Iraq six weeks from now, and fears about whether an interim government established during wartime conditions will survive.

But Myers expressed faith that the Iraqis will rally to their new government. "I think that as the new transitional government stands up, that there will be traction there with the Iraqi people that will be very important to them," he said.

The general also asserted, without citing evidence, that most Iraqis know that the only reason the U.S. military is in Iraq is to help bring peace to the country. "I think the majority of Iraqis understand that," he said.

That assertion appears to conflict with a recent poll conducted for the U.S. occupation authority in Iraq, which found that 82 percent of Iraqis have a negative view of U.S. and allied forces. The poll was taken before the prisoner-abuse situation became a major scandal.

Myers did see a few clouds on the Iraq horizon. "I think there will continue to be a big security threat to progress in Iraq past 30 June, clearly," he said.

He also expressed specific concern about signs of growing cooperation among disparate Iraqi insurgent groups, such as Shiite extremists and loyalists to deposed president Saddam Hussein's Baath Party. "We are seeing, I think, more coordination between them . . . tactical agreement that they can help one another, share weapons and so forth," he said.

Myers also defended the outcome of the fighting in the troubled western Iraqi city of Fallujah, where the Marine Corps turned over control to a former Iraqi general -- a move that has puzzled some inside the military and some outside defense experts. For example, Thomas Donnelly, an Iraq hawk who is a security analyst at the American Enterprise Institute, said in an interview: "The quasi-retreat is potentially very bad. I don't think you can fool the American people into thinking that Fallujah is a famous victory."

But Myers argued that "this is the right way to do it." Sometimes, he explained, a nuanced use of force is needed. "We need to know when to use force. We need to know when to back off," he said.

He specifically noted that the agreement in Fallujah gives Baathists some hope of reclaiming a place in Iraqi society short of violence. "I think what you're seeing in Fallujah now is part of that process, to give these people that provided a lot of the senior leadership to Saddam's regime, you're giving them hope that there is a way forward without just fighting the coalition," he said.

Democrats on the committee seemed less inclined to accept Myers's broad assertions of progress in Iraq than they have been in the past. "I just can't sit here any longer, with all due respect, General Myers, and take people's assertions that things are being taken care of when this thing has been botched so badly so far," said Rep. Ellen Tauscher (Calif.).

Gen. Richard B. Myers, the Joint Chiefs chairman, tells lawmakers there is "great progress" in Iraq.