Former Sen. Chuck Hagel began confirmation hearings for his nomination to be Secretary of Defense. He sparred with Sen. John McCain over whether the surge during the Iraq war was worthwhile. (Jan. 31)

Phil Stewart and Patricia Zengerle Reuters

12:05 p.m. CST, January 31, 2013

WASHINGTON (Reuters) - Republican lawmakers clashed with Chuck Hagel on Thursday at a hearing over his nomination to become the next U.S. defense secretary, attacking his judgment on war strategy and occasionally putting him on the defensive during a heated session.

Critics in Congress have sought to portray Hagel, a former Republican senator and decorated Vietnam War veteran, as soft on Iran and anti-Israel, charges Hagel strongly denied in testimony at the Senate Armed Services Committee hearing.

Republican panel members laid into Hagel, with influential Senator John McCain threatening to vote against him as he questioned Hagel's judgment on the wars in Iraq and Afghanistan, where Hagel opposed surges of American forces.

Even before Hagel started speaking, James Inhofe, the panel's senior Republican, called him "the wrong person to lead the Pentagon at this perilous and consequential time."

"Senator Hagel's record is deeply troubling and out of the mainstream. Too often it seems he is willing to subscribe to a worldwide view that is predicated on appeasing our adversaries while shunning our friends," said Inhofe.

The committee also dwelt on chapters of modern U.S. history that still prompt passionate debate: from the Vietnam War, where Hagel served as an infantryman and was wounded, to President Ronald Reagan's call for nuclear disarmament and the 2003 invasion of Iraq.

Hagel, speaking publicly for the first time since the attacks against his nomination began, at times seemed cautious and halting. He sought to set the record straight, assuring the panel that he backed U.S. policies of preventing Iran from obtaining a nuclear weapon and supporting a strong Israel.

"No one individual vote, no one individual quote, no one individual statement defines me, my beliefs, or my record," Hagel said to the packed hearing room.

"My overall world view has never changed: that America has and must maintain the strongest military in the world."

In an unusual reversal of partisanship, Democrats, more than his fellow Republicans, gave Hagel sympathetic support and time to air his views.

The committee's Democratic chairman, Carl Levin, said his concerns, especially over Hagel's past comments about unilateral sanctions on Iran, had been addressed. "Senator Hagel's reassurance to me ... that he supports the Obama administration's strong stance against Iran is significant," Levin said.

Another member of Obama's second-term national security team, Senator John Kerry, sailed through his nomination hearing before receiving the Senate's overwhelming support on Tuesday.

But Hagel, who publicly broke with his Republican Party over the Iraq War, encountered repeated confrontation. Beyond tough questioning on Israel and Iran, he was also grilled on his view of the Pentagon budget - Hagel is known as an advocate for tighter spending controls.

THE IRAQ SURGE

McCain aggressively questioned Hagel, talking over him at times, and gesturing to express frustration at Hagel's refusal to say plainly whether he was right or wrong in opposing the 2007 surge of American forces in Iraq.

"Your refusal to answer whether you were right or wrong about it is going to have an impact on my judgment as to whether to vote for your confirmation or not," McCain said.

Pressed repeatedly by McCain on the issue, Hagel responded: "I would defer to the judgment of history to sort that out."

It was a far cry from their past, warm ties. McCain campaigned for Hagel in 1996, and Hagel was national co-chairman of the Arizona Republican's unsuccessful 2000 presidential bid.

On Thursday, McCain warned that concerns about Hagel's qualifications ran deep, noting "fundamental disagreements" with members of the committee.