A day after his confirmation by the U.S. Senate, Chuck Hagel has been sworn in as U.S. defense secretary.
Tuesday's final vote on the former senator's nomination came nearly two weeks after his former Republican colleagues delayed a full vote, raising concerns about his views on the Middle East and the size of the U.S. nuclear arsenal.
Some of them accused Hagel of being too lenient toward Iran and too critical of Israel. Others also found fault with him for opposing the 2007 U.S. troop surge in Iraq.
Republicans eventually put aside their criticisms, though, and allowed Hagel's nomination to be put to an "up or down" vote.
President Barack Obama praised the confirmation, saying the United States will, in his words, "have the defense secretary our nation needs and the leader our troops deserve."
Hagel assumes the post at a challenging time for the Pentagon, which is facing major budget cuts as the war in Afghanistan comes to an end. The military also is facing the immediate loss of billions of dollars if a series of across-the-board automatic spending cuts, known as the "sequester," takes effect this Friday.
Hagel succeeds retiring Pentagon chief Leon Panetta. Hagel will be the first Vietnam War veteran and the first former enlisted soldier to serve as Pentagon chief.
"The president needs a secretary of defense in whom he has trust, who will give him unvarnished advice, a person of integrity and one who has a personal understanding of the consequences of decisions relative to the use of military force. It is time to end the uncertainty relative to leadership at the Pentagon," said Carl Levin. "The time has come to now confirm Chuck Hagel as our next secretary of defense and I hope that the Senate will on a bipartisan basis soon do exactly that.''
U.S. President Barack Obama and Vice President Joe Biden (R) applaud Defense Secretary Chuck Hagel after the president announced Hagel's resignaton at the White House in Washington, Nov. 24, 2014.
Defense Secretary Chuck Hagel speaks during a news conference at the Pentagon, Washington, Nov. 14, 2014.
Defense Secretary Chuck Hagel talks to marines at a training range as he observes an experimental infantry unit that is going to help assess which combat jobs can be opened to women in 2016, Camp Lejeune, North Carolina, Nov. 18, 2014.
Defense Secretary Chuck Hagel, accompanied by Joint Chiefs Chairman Gen. Martin Dempsey, testifies on Capitol Hill before the House Armed Services committee hearing on the Islamic State militants, Washington, Nov. 13, 2014.
President Barack Obama, next to Defense Secretary Chuck Hagel, speaks to the media about Ebola during a meeting in the Cabinet Room of the White House in Washington, Oct. 15, 2014.
Defense Secretary Chuck Hagel speaks to service members and civilian employees at the Pentagon after being sworn in, Feb. 27, 2013.
Outgoing Senator Chuck Hagel greets supporters after a farewell news conference in Omaha, Nebraska, December 18, 2008.
Then Democratic presidential candidate Barack Obama, David Petraeus, and Chuck Hagel ride in a helicopter, Baghdad, Iraq, July 21, 2008. (US Army)
Then President George W. Bush and then Senator Chuck Hagel embrace at the Airlite Plastics Company in Omaha, Nebraska, May 12, 2003.
Then Senator Chuck Hagel, left, and Senator John Kerry, shake hands while with other senators who served in Vietnam at the 15th anniversary of the Vietnam Veterans Memorial, March 7, 1997.
Chuck Hagel (right) standing outside tents in Vietnam, circa 1968. (Library of Congress)