President-elect Trump is quickly lining up Cabinet nominees for his next administration, including China hawks and hard-line Israel supporters in key national security and foreign policy roles.

But as of Tuesday evening, the key role of his next Pentagon chief remained up in the air.

A number of names have been floated in Washington, including well-known figures in Congress — such as House Armed Services Committee Chair Mike Rogers (R-Ala.) and Sen. Joni Ernst (R-Iowa), an Army National Guard veteran — along with loyalists who held Pentagon posts during Trump’s first term, such as his final acting Defense Secretary Christopher Miller.

The ultimate pick will head Trump’s plans to reshape the Defense Department at a time of global upheaval, with conflicts in Ukraine and the Middle East, an increasingly belligerent North Korea and Iran, and a China that continues to threaten Taiwan and encroach on contested areas in the Indo-Pacific.

Trump and his allies have railed against so-called woke policy and efforts within the U.S. military implemented by the Biden administration and lawmakers, including the renaming of military bases formerly named after Confederate generals; diversity, equity and inclusion initiatives; the Pentagon’s abortion travel policy; and allowing transgender service members to join the ranks. His next Pentagon pick is sure to help dismantle many of these initiatives.

The next Pentagon chief also would step into a role that proved volatile under Trump’s last term. Five men held the job as Defense secretary during that time, but one resigned, one was fired and another three served as in-betweens but were never confirmed by the Senate.

Christopher Miller 

A retired Army Special Forces officer and acting Defense secretary during Trump’s final two months in the White House, Miller stands as an obvious if not reluctant pick to lead the Defense Department.

Known more recently as the author of the defense chapter of Project 2025, an outline of conservative priorities created by the Heritage Foundation, Miller has also run the National Counterterrorism Center.

Last year, Trump even dropped hints that Miller would be in the running for his next possible Pentagon chief.

“We had Miller at the end who did a very good job,” Trump told conservative radio host Hugh Hewitt in December 2023. “I thought he was really good. I thought he was very good.”

Miller’s Defense tenure, which lasted from November 2020 to January 2021, was particularly eventful. He notably announced Trump’s long-wanted troop drawdown in Afghanistan and Iraq, something his predecessors had resisted, and was criticized as not acting quickly enough in sending National Guard troops to the Capitol during the attacks on Jan. 6, 2021.

But Miller himself has expressed tepid interest in taking over as the Pentagon’s top civilian, with Defense One reporting last week that he “displays annoyance both at the question of what role he might play in a future Trump administration and, it seemed, at the very possibility.” 

Keith Kellogg

Retired Army Lt. Gen. Keith Kellogg, another Trump loyalist and key adviser, is entrenched in the president-elect’s orbit and has a deep national security background.

On Trump’s last go-around from 2017-2021, Kellogg served on his Pentagon transition team, was national security adviser to then-Vice President Mike Pence, and, as the executive secretary and chief of staff of the National Security Council, took over as acting national security adviser following the resignation of Michael Flynn in 2017.

More recently, Kellogg was one of two key Trump advisers to help craft a plan to end Russia’s war in Ukraine, a roadmap presented to the incoming president in June that involves telling Kyiv it will only get more U.S. weapons if it enters peace talks. 

Elbridge Colby

Colby, who served as the deputy assistant secretary of Defense for strategy and force development in the last Trump administration, is another whispered option in Republican circles.

Known for being a lead architect of the 2018 National Defense Strategy, a document that called for far more emphasis on deterring and defeating China, he’s been vocal in pressing Taiwan to spend more on its defenses. 

“Those who care about Taiwan should be super clear they need to dramatically step up. Their fate hangs in the balance,” he wrote on the social platform X in September.

And on Tuesday he wrote on X that the U.S. “can get to a much better place with our allies on defense spending if we hold them to account.”

Such a stance is likely to win points with Trump, who has often railed against U.S. allies and partners not pulling their weight when it comes to defense spending.

The Harvard University and Yale Law School graduate also made waves in GOP circles when, shortly after the election, he appeared on the podcast of former Fox News host Tucker Carlson, where he spoke at length on Trump’s foreign policy vision.

Posting about the episode afterward, Carlson, an influential voice within Trump World, declared Colby “one of the very few experienced national security officials who actually agrees with Donald Trump. He’s likely to play a big role in the new administration.”

Rep. Mike Rogers

The chair of the House Armed Services Committee since 2023, Rogers, an Alabama Republican, is a dark-horse contender for the post.

Rogers has been a staunch defender of Trump and aligns with the incoming commander in chief on a number of national security issues, including space defense, rolling back Biden-era Pentagon climate programs and repealing personnel policies such as troops’ access to abortion.

But the lawmaker is not as personally close to Trump as other contenders and splits from him on one major issue: Ukraine.

While Trump has railed against new funding for Kyiv, insisting he will quickly negotiate an end to its war with Russia, Rogers has been a strong advocate of U.S. assistance for Ukraine. Even as those in his party soured on sending more aid to the war-torn country, Rogers held oversight hearings to show that the U.S. dollars were being put to good use. 

Math in the House could also hurt Rogers’s chances. Trump has been urged by House GOP leadership to not pick any more Republican members for his administration given the already slim majority.

Trump has already named two members, House Republican Conference Chair Elise Stefanik (N.Y.) and Rep. Mike Waltz (R-Fla.), to roles in the new administration, as U.N. ambassador and national security adviser, respectively.

“President Trump and I have talked about this multiple times a day for the last several days. … I don’t expect that we will have more members leaving,” Speaker Mike Johnson (R-La.) told reporters Tuesday.

Sen. Joni Ernst

Reports emerged this week that Ernst, Iowa’s junior senator, is interested in serving as Defense secretary, a position, if confirmed, that would make her the first female Pentagon chief in U.S. history.

The nonprofit publication NOTUS, funded by the Allbritton Journalism Institute, first reported Monday that Ernst had privately expressed interest in the job and that national security leaders had approached her and relayed that she would be a good fit.

Ernst’s office, however, on Tuesday sought to brush aside the speculation, with a spokesperson telling The Des Moines Register that she is “laser-focused” on her Senate work.

“Washington’s rumor mill will never stop churning, but Sen. Ernst is laser-focused on serving Iowans and her colleagues as conference chair and carrying out President Trump’s agenda in the Senate,” Palmer Brigham said in a statement.

Ernst, ranked fourth in Senate GOP leadership, is currently serving her second term after first winning in 2014 and again in 2020. 

A member of the Senate Armed Services Committee with a deep military background, she served in the Iowa Army National Guard from 1993 to 2015 before retiring as a lieutenant colonel. While in the service, she deployed to Kuwait during the Iraq War. 

This week’s reports that she is interested in becoming Pentagon chief comes with little surprise as she has said she would be open to serving in the Trump administration.

“It would be such an honor to be asked to work in an administration,” she said in June. “So, I would be open to whatever the president — if he asked, I would certainly be willing to respond.”