Washington ? After a long day of questions – and speeches masquerading as questions – the final hour of a Senate hearing featuring the Iraq war commander produced a revealing moment.

With TV cameras trained on Gen. David Petraeus in a packed room on Capitol Hill, Sen. George Voinovich, Republican from Ohio, noted the enormous expense of a war that has lasted more than five years, taken more than 4,000 American deaths and cost hundreds of billions of dollars.

“The American people have had it up to here,” Voinovich declared, “we’re stressed out” from a conflict that seems to have no end in sight.

Petraeus, who has spent more time in Iraq than any other general, didn’t argue.

“I certainly share the frustration,” he said.

And yet, the bottom line of Petraeus’ message Tuesday at back-to-back Senate hearings was that it’s still too early to promise further withdrawals of U.S. troops because Iraq remains in danger of returning to chaos.

He painted a picture of a nation struggling to suppress violence among its own people and to move toward the political reconciliation that President Bush said a year ago was the ultimate aim of his revised Iraq strategy, which included sending more than 20,000 extra combat troops.

Security is getting better, and Iraq’s own forces are becoming more able, Petraeus said. But he also ticked off a list of reasons for worry, including the threat of a resurgence of Sunni or Shiite extremist violence. He highlighted Iran as a special concern, for its training and equipping of extremists.

Petraeus was told by a parade of Democrats that, after five years of war, it was past time to turn over much more of the war burden to the Iraqis. Those senators said Iraq will not attain stability until the United States makes the decision to begin withdrawing in large numbers and forces the Iraqis to settle their differences.

But when it came to predicting a timetable for further withdrawals, Petraeus didn’t budge. He said he had recommended to Bush that he complete, by the end of July, the withdrawal of the 20,000 extra troops. Beyond that, the general proposed a 45-day period of “consolidation and evaluation,” to be followed by an indefinite period of assessment before he would recommend any further pullouts.

The Petraeus plan, which Bush is expected to embrace, reflects a conservative approach that leaves open the possibility that roughly 140,000 U.S. troops could remain in Iraq when the president leaves office next year.

One of three senators who could be the new president by January, Hillary Rodham Clinton, said earlier, not in a response to Petraeus, that she disagreed with those who criticized lawmakers who are calling for an orderly withdrawal.

“Rather, I think it could be fair to say that it might well be irresponsible to continue the policy that has not produced the results that have been promised time and time again at such tremendous cost to our national security and to the men and women who wear the uniform of the United States military,” she said.

Sen. Barack Obama, her rival for the Democratic presidential nomination, told Petraeus that while he wants U.S. troops out of Iraq he would not initiate a precipitous withdrawal. And he said talking regularly to the Iranians is critical to getting to the point where it would be safe to end American involvement.

“I do not believe we are going to be able to stabilize the situation without them,” Obama said.

John McCain, who will be the GOP nominee, said: “Our goal – my goal – is an Iraq that no longer needs American troops. And I believe we can achieve that goal, perhaps sooner than many imagine. But I also believe that to promise a withdrawal of our forces, regardless of the consequences, would constitute a failure of political and moral leadership.”