WASHINGTON -- When Lt. Gen. David Petraeus came before the Senate Armed Services Committee last week in open session, its members understandably had many questions for the new commander of American forces in Iraq.

They knew of his reputation as a battlefield leader, a trainer of Iraqi troops and the author of the Army manual on counterinsurgency warfare. They also recognized the difficulty and importance of his new assignment.

Many of the questions probed deeply into the rationale for the president's new strategy of injecting more U.S. troops into Baghdad neighborhoods wracked by killings by rival Sunni and Shiite gangs. Others challenged the readiness of Iraqi forces and the Baghdad government to do their part in reducing sectarian violence.

A few of the questions were naive, self-serving or off on tangents. But virtually the entire membership of the committee was present and senators of both parties recognized the value of probing this experienced and candid witness.

With one exception. Sen. Hillary Rodham Clinton of New York used her time to make a speech about Iraq policy and did not ask a single question of the man who will be leading the military campaign.

Her speech replayed some of the themes from her news conference the previous week, on her return from Iraq, when she made clear her disagreement with President Bush's decision to add 21,500 soldiers and Marines to Petraeus' force.

She began by blaming the Iraq crisis on a "Congress (that) was supine under the Republican majority, failing to conduct oversight and demanding accountability, and because the president and his team, particularly the former secretary of defense (Don Rumsfeld), refused to adapt to the changing circumstances on the ground."

From that partisan opening, Clinton went on to decry "the failures of the Iraqis to step up and take responsibility for their own future." She said the escalation Bush ordered was too little and too late, and instead called on Congress to "threaten to cut money for the Iraqi troops and for the security for the Iraqi leadership," as a way to break the political gridlock in Baghdad and force efforts at national reconciliation.

She wound up the speech by saying that despite her disagreement with the policy, she wanted Petraeus' assurance that "we have every possible piece of equipment and resource necessary to protect these young men and women" going into battle.

"I'll do that, senator," Petraeus said, and after that four-word response, Clinton was finished. She had no questions to ask.

Judging by all the polls, Clinton is the leading candidate for the Democratic presidential nomination. Sen. John McCain of Arizona, a leading candidate for the Republican nomination, is also a member of the Armed Services Committee.

McCain asked Petraeus 14 questions, ranging from the political situation in Iraq to the morale of the troops to the time line for the planned "surge." He ran out of time before he ran out of questions -- quite a contrast to Clinton.

Clinton aides said the senator thought it was important to rebut the comments from several other committee members suggesting that congressional resolutions opposing the president's policy would "undercut the troops," so she used her time for that purpose. But I can think of three other possible explanations for her remarkable reluctance to probe the general's thinking.

First, she has been treading a careful line from her early support of military action against Saddam Hussein to an increasingly sharp criticism of the war and calls for troop reductions. Perhaps she feared that dialogue with Petraeus would lead her into dangerous, uncharted waters. Caution is commendable, but she is sometimes faulted for being too calculating.

Second, the hearing came only three days after she announced her presidential exploratory committee, and she may have decided it was a good opportunity to repeat her views on Iraq policy before TV cameras rather than share time with the general. That wouldn't say much about her priorities as she begins a second six-year term as senator, but New York voters last November presumably knew she might have loftier goals than just minding her Senate duties.

The third, less-benign possibility is that Clinton is reverting to the mode of her ill-fated 1993-94 health-care initiative, when she gave members of Congress and other interested folks the impression that she thought she had all the answers -- so please just do as I say. In that period, she and her deputy, Ira Magaziner, two of the smartest policy wonks in captivity, were also supremely self-confident -- and in some eyes, arrogant. And it cost them support, even among potential allies.

Last week, Clinton began her presidential campaign, as she did her first race for the Senate in New York, by saying she wanted to do a lot of listening. She sure wasn't listening to Gen. Petraeus. She wasn't even asking.

David Broder's e-mail address is davidbroder@washpost.com.