Updated at 5:53 p.m. ET – Former Sen. Chuck Hagel, President Barack Obama’s choice to be secretary of defense, finished a day-long marathon confirmation hearing before the Senate Armed Services Committee Thursday, enduring nearly eight hours of testy and skeptical questions from Republicans.

At the start of Thursday’s hearing, it seemed nearly certain that the Senate would vote to confirm Hagel. But the nominee labored at certain points during the day to clarify and explain his comments. Whether his occasional stumbles were serious enough to jeopardize his confirmation was not clear by the end of the testimony.

There are 55 senators in the Democratic caucus and 45 Senate Republicans, so if there’s no filibuster, Hagel would seem assured of confirmation. The last time the Senate rejected a Cabinet nominee was in 1989 when there was a Republican president and a Democratic-controlled Senate. 

Republican senators confronted Hagel with quotations from statements he had made months or years ago – and sometimes he apologized for them or amended them.

Late in the day Sen. Mike Lee, R- Utah, asked Hagel whether he’d said in 2003 that Israel keeps Palestinians “caged up like animals” and whether he still believes that.

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“Like many things I’ve said, I would like to go back and change the words and the meaning,” Hagel told Lee. “If I had a chance to go back and edit it, I would. I regret that I used those words.”

But he said he’d made his statement “in a larger context … (addressing) the frustration in what’s happening (in Israel) which is not in Israel’s interest” and mentioned the need “to find ways that we can help bring peace and security to Israel.”

Quizzed by both Sen. Kirsten Gillibrand, D-N.Y., and Sen. David Vitter, R- La., on a statement he’d made calling the Iranian government a “legitimate” one, Hagel said, “I should have said ‘recognized’ instead of ‘legitimate.’”

At one point he told Sen. Saxby Chambliss, R- Ga., regarding U.S. policy toward Iran’s efforts to build nuclear weapons: “I’ve just been handed a note that I misspoke and said I supported the president’s position on ‘containment.’ If I said that, I meant to say that obviously – his position on containment – we don’t have a position on containment.”

Hagel then said, “I’ve had more attention paid to my words in the last eight weeks than I ever thought possible.”

This prompted Armed Services Committee chairman Sen. Carl Levin, D- Mich., to intervene, “Just to make sure your correction is clear, we do have a position on containment – which is we do not favor containment.” Hagel quickly concurred with Levin’s statement.

Hagel told the panel in his opening remarks that he is “fully committed to the president's goal of preventing Iran from obtaining a nuclear weapon,” and that “all options must be on the table to achieve that goal. My policy is one of prevention, and not one of containment and the President has made clear that is the policy of our government.”

At another point, Hagel, explaining his criticism quoted in a 2008 book by Aaron David Miller, of “the Jewish lobby” and his allegation that “it intimidates a lot of people” in Congress – comments for which Hagel has apologized – said he ought to not have used the word “intimidates.”

“I should have used ‘influence,’” he said.

Later, Sen. Lindsey Graham, R- S.C., challenged Hagel to “name one dumb thing we’ve been goaded into doing” by the pro-Israel lobby or to identify one member of Congress whom the pro-Israel lobby had intimidated. Hagel said, “I didn't have in mind a single person," and did not identify any policy the U.S. government had been goaded into.

Sen. Ted Cruz, R-Texas, played Hagel a recording of an interview Hagel did in 2009 with an al Jazeera program. A listener submitted a question asking about “the image of the United States is that of the world’s bully” and whether the United States needed “to change the perception and the reality” before asking other nations to reduce their arsenals. In that 2009 program Hagel began his reply by saying, “Her observation is a good one … .”

When Cruz asked Hagel to explain this reply, he said Thursday, “I think my comment was it was a relevant and good observation. I don’t think I said that I agree with it.”

Early in the testimony, the Iraq war and President George W. Bush’s 2007 surge of U.S. troops into Iraq became the heated focus of the hearing.

Sen. John McCain, R- Ariz., repeatedly pressed Hagel, a fellow Vietnam War veteran, on whether he had been right or wrong to say that the 2007 surge was “the most dangerous foreign policy blunder since Vietnam.”

When McCain angrily said “Will you please answer the question?” Hagel told McCain “I’m not going to give you a yes or no answer … I’ll defer that judgment to history.”

When McCain shot back that Hagel had been wrong about the surge, Hagel said his “most dangerous blunder” comment had been “not just about the 2007 surge but the overall war of choice going into Iraq” in 2003.

As a senator, Hagel voted for the congressional resolution authorizing Bush to invade Iraq, but later turned critical of Bush’s conduct of the operation.

Other Republicans on the committee repeatedly pressed Hagel on his support for endorsement of Global Zero, the movement calling for abolition of nuclear weapons by 2030.

Hagel served on the Global Zero U.S. Nuclear Policy Commission which issued a report last May calling for an 80 percent reduction in the U.S. nuclear arsenal.

Hagel told ranking Republican committee member Sen. Jim Inhofe of Oklahoma that his position “has never been unilateral disarmament.”

Kevin Lamarque / Reuters

Former Senator Chuck Hagel, R-Neb., testifies during a Senate Armed Services Committee hearing on his nomination to be Defense Secretary, on Capitol Hill, Jan. 31, 2013.

And he said the Global Zero report was discussing “illustrative possibilities” and “scenarios” and wasn’t urging specific policies.

But last May’s Global Zero report, which Hagel signed on to, says that a drastically smaller U.S. arsenal could be negotiated bilaterally with Russia – “or implemented unilaterally.”

In his opening statement Hagel pledged that he would maintain an effective nuclear arsenal. “America's nuclear deterrent over the last 65 years has played a central role in ensuring global security and the avoidance of a World War III. I am committed to modernizing our nuclear arsenal,” he said.

Hagel, who was seriously wounded while serving as an Army infantryman in Vietnam, was a Republican senator from Nebraska from 1997 to 2009 but did not support Republican presidential candidates McCain in 2008 or Mitt Romney last year.