How Trump and Hegseth could change the US military and the challenges they might face

President-elect Donald Trump and his pick to lead the Defense Department, Pete Hegseth, have proposed major changes to the U.S. military, leading to questions about how the department could be affected in a second Trump administration.

Here are five areas that could see significant impact, as well as the obstacles such initiatives could face.

Women in combat roles

Ahead of his selection by Trump to lead the DOD, Hegseth spoke out against women serving in ground combat roles.

"I love women service members, who contribute amazingly," Hegseth said during a podcast appearance earlier this month. But three minutes later, he added, "I'm straight up just saying we should not have women in combat roles. It hasn't made us more effective, hasn't made us more lethal, has made fighting more complicated."

"It is our understanding that it is theoretically possible for the executive branch to roll back the rules allowing women to serve in combat units," a congressional aide told ABC News on Monday.

While Congress could move to create a law enshrining female combat service, "it doesn’t exist at the moment,” the aide said.

Getting such a law passed could be an uphill battle, and even a law might not be enough, according to Lory Manning, former director of government operations for the Service Women's Action Network, who has long focused on the issue.

"The services could ignore it," Manning said of a potential law. "Whether there's a law or not, there's a way around it."

Of the active-duty military personnel, 17.5% are women, and women make up 21.6% of the selected reserve, according to the Pentagon's latest statistics. Thousands of women have now served in combat roles.

Allowing women to serve in ground combat units was triggered both by laws enacted by Congress and policy decisions, beginning with the 1948’s Women’s Armed Services Integration Act.

The act allowed women to serve in the U.S. military but had limits on the percentage of women in the force and prohibited them from serving in combat. Things stayed in place up until the early 1990s, when then-Defense Secretary Les Aspin rescinded the "Risk Rule" and allowed women to serve as pilots in all types of situations, including combat.

There weren’t any further changes for another two decades, until 2013 and 2016, when the DOD made policy changes triggered by another law, the 2011 National Defense Authorization Act. That legislation required the DOD to “conduct a review of laws, policies, and regulations that may restrict the service of female members of the Armed Forces; and ... report review results.”

Those reviews led Defense Secretary Leon Panetta to lift what was known as the “ground combat exclusion rule." His action and the 2016 action by Defense Secretary Ash Carter were policy decisions, which means they could be changed by future defense secretaries.

Hegseth has said he is not against women serving as combat pilots or in female engagement teams on the ground, but if confirmed as secretary of defense he could give an order to close other combat jobs that were opened by his predecessors, like those in the infantry and special operations forces.

Firing generals

Hegseth, who would need to be confirmed by the Senate before becoming secretary, has suggested the firing of America's top military officer, the chairman of the Joint Chiefs of Staff, Air Force Gen. CQ Brown. He has likewise called for the removal of other senior officers, particularly those involved in the chaotic withdrawal from Afghanistan or "woke" diversity, equity, and inclusion (DEI) initiatives.

"First of all, you got to fire the chairman Joint of the Chiefs and obviously going to bring in a new secretary of defense, but any general that was involved -- general, admiral, whatever -- that was involved in any of the DEI woke s--- has got to go," Hegseth said during an interview days before being nominated. "Either you're in for war-fighting, and that's it. That's the only litmus test we care about."

The president has a lot of latitude here. While there could be legal challenges in trying to outright kick generals or admirals out of the military, should they refuse a request to resign, the commander in chief has the authority to remove any general from their current position and reassign them.

Three- and four-star generals or admirals only hold those ranks while in certain senior leadership roles. So, if they are reassigned to a lesser position, it would mean at minimum a reduction in rank, which would in turn mean a reduction in pay then and in retirement. And such relief of command is generally a career-ender.

A president can only fully dismiss an officer during times of war. Otherwise, a court-martial process is required, according to U.S. code.

Still, an officer's influence and career path could be completely derailed at the discretion of the president, even without total dismissal.

Transgender service

In 2016, the Pentagon under then-President Barack Obama lifted restrictions on transgender people serving in the armed forces. But in 2017, Trump announced on what was then Twitter that transgender service members would no longer be able to serve openly in the armed forces, citing concerns over costs and readiness. The policy was implemented in 2019 and required transgender service members to serve in line with their biological sex unless they had already successfully transitioned or were grandfathered in under the Obama-era policy.

In 2021, the Trump policy was reversed under the Biden administration, allowing transgender service members to again serve openly and access related medical care.

"This change to the standards meant that men and women could join the military for the express purpose of transitioning, be nondeployable for a year, and take life-altering hormone therapy that would mean they would be nondeployable unless the military could guarantee the supply of medication," Hegseth said of the changes under Biden in one of his books.

When he retakes office, Trump could reinstate his transgender military ban by executive order to the DOD by again citing cost or readiness concerns, which in turn would likely trigger new legal challenges.

A Rand study commissioned by the Obama administration in 2015 estimated gender-transition care would cost the department between $2.4 million and $8.4 million per year, a small fraction of a percent increase to total military health expenditures. The study also found that postoperative recovery and other transition-related factors could limit service members' ability to deploy, but it noted that because only a small number of troops would be likely to transition, the overall impact to military readiness would be minimal.

In Trump's first term, several lawsuits were filed in federal court arguing the ban violated constitutional protections, with courts issuing injunctions to block the policy temporarily while litigation continued.

Then, in early 2019, the U.S. Supreme Court allowed the ban to go into effect, with some exceptions, while legal appeals continued. Lower courts were divided, and those service restrictions remained in place until the Biden reversal.

If Trump does try to restrict transgender service, it's likely that the outcome will depend on the courts. The GOP in Congress could try to codify a transgender ban in law, but this would face its own hurdles.

Pentagon abortion travel policy

After Roe v. Wade was overruled, the Pentagon under Biden created a policy aiming to allow service members stationed in states that had banned abortions to have access to the procedure. The policy offers women paid time off and reimbursement for travel costs to receive abortions and other reproductive health care out of state.

Trump would have the power to rescind the policy. The president has broad authority to dictate administrative military policies such as leave, travel and health care. Lawsuits could still arise but might have a low chance of succeeding since there's no federal law mandating the abortion travel policy.

Renaming bases after Confederate generals

Just last month, Trump vowed to change Fort Liberty, an Army base in North Carolina, back to Fort Bragg, named after Confederate Gen. Braxton Bragg. A possible complication to Trump's promise is that the 2021 National Defense Authorization Act established a law requiring that Confederate names be removed from military installations.

However, although that legislation mandated the removal of Confederate names, it did not eliminate the naming authority of the executive branch, leaving open the possibility of a power struggle between the White House and Congress in the future.