Pete Hegseth was sworn in Saturday as the nation’s 29th secretary of defense, quickly joining President Trump’s Cabinet after a dramatic late-night vote in the Senate installed him as the Pentagon’s leader.

Hegseth took the oath from Vice President JD Vance in the Eisenhower Executive Office Building with Hegseth’s wife, Jennifer Rauchet, at his side and Republican senators looking on. The ceremony came less than 12 hours after Vance broke a 50-50 tie in the Senate to narrowly seal Hegseth’s confirmation.

Hegseth Outlines Guiding Principles

In brief remarks, Hegseth outlined what he said were his guiding principles: “Restore the warrior ethos in everything that we do, rebuild our military and reestablish deterrence.”

“We don’t want to fight wars,” he added. “We want to deter them … and we want to end them responsibly. But if we need to fight them, we’re going to bring overwhelming and decisive force to close with and destroy the enemy and bring our boys home.”

He thanked Vance for his tiebreaking vote and joked that his children were happy their father “won in overtime.”

“It is the honor of a lifetime, sir, to serve under you,” Hegseth said, in thanking Trump, who was in Las Vegas on Saturday.

Later, in a emailed message to the American military, he said “we will remain the strongest and most lethal force in the world” and he singled out the needs “to deter aggression in the Indo-Pacific by Communist China … and reorient to key threats. We will stand by our allies — and our enemies are on notice.”

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Narrow Confirmation Amid Concerns

The unusually narrow confirmation for a defense secretary came after questions from members in both parties over Hegseth’s qualifications to lead the military, especially amid allegations of heavy alcohol use and aggressive behavior toward women.

For Hegseth, the challenges ahead are steep, as he takes charge of a sprawling bureaucracy at a time of severe challenges around the globe.

He enters office with far less experience than modern defense secretaries before him, acknowledging during his confirmation hearing that he’ll need to build an experienced team as he settles into the job. “I want smarter and more capable people around me than me, and you will get that at the department,” he said in his testimony.

Hegseth also lacks the broad bipartisan support that most have brought to the role. Every Senate Democrat voted against Hegseth’s confirmation, as did three Republicans deeply skeptical of his qualifications for the job.

Adding to the acrimony, Hegseth refused to meet with any Democrats before confirmation, breaking from tradition.

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Concerns Over Experience and Behavior

Rarely has a Cabinet nominee faced such wide-ranging concerns about his experience — having been a combat veteran, veterans advocate and Fox News host — as well as behavior as Hegseth, particularly for such a high-profile role atop the U.S. military.

But the Republican-led Senate was determined to confirm Hegseth and round out Trump’s top national security team.

Democrats, the minority in the Senate, had helped confirm Secretary of State Marco Rubio and CIA Director John Ratcliffe in bipartisan votes. But they fiercely opposed Hegseth, with even the top Democrat on the Armed Services Committee refusing to support him.

Reacting to the vote, Senate Democratic leader Charles Schumer of New York said Republicans have “entrusted the most powerful military in the world to someone with no experience, terrible judgment and serious flaws of character.”

“I hope for the sake of our troops and the good of our country that he can eventually grow into the job,” Schumer said on the Senate floor.

Three Republicans — Sens. Mitch McConnell of Kentucky, Susan Collins of Maine and Lisa Murkowski of Alaska — also voted against Hegseth, questioning his qualifications for the job.

Hegseth faced allegations that he sexually assaulted a woman at a Republican conference in California, though he has denied the claims and said the encounter was consensual. He later paid $50,000 to the woman.

Hegseth also had promised during his confirmation hearings that he would not drink while on the job, were he to be confirmed.

Meanwhile, his opposition to women in combat became an issue after Trump announced his choice in November. But, in the face of questions from Congress, Hegseth appeared to shifted.

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Asked about the issue on the “Megyn Kelly Show” in early December, Hegseth said he cares only that military standards are maintained. Women serve in combat, he said, and, “if we have the right standard and women meet that standard, roger. Let’s go.”

Hegseth told senators that he supports women in the military but wants to review standards to make sure they are not lowered to accommodate women.

At the swearing-in ceremony, a question directed to Hegseth about why women in the armed services should trust him was answered by Vance.

“All people in our armed services should trust him because he looks out for them and he is going to fight for them,” Vance said.