Hegseth, a Princeton and Harvard graduate, served for about two decades in the U.S. Army Reserve and the National Guard in New Jersey, New York, Minnesota, Massachusetts, and the District of Columbia from May 2001 to March 2021. He deployed to Guantanamo Bay, Iraq, and then Afghanistan in that order, according to a spokesperson with the National Guard Bureau.

Almost immediately following Trump’s announcement that he picked Hegseth to be his nominee to lead the Pentagon, critics quickly highlighted the Fox News host’s lack of experience when it comes to managing bureaucracy, let alone one the size of the Pentagon.

The secretary of defense leads more than 1.4 million active-duty service personnel and more than 700,000 National Guard and reservists. About the same number of civilians who work in the Pentagon, bringing the number of people within the department to nearly 3 million with a budget believed to be approaching a trillion dollars annually in the near future.

“A Fox & Friends weekend co-host is not qualified to be the Secretary of Defense,” Senate Democrat Elizabeth Warren (D-MA), said. “I lead the Senate military personnel panel. All three of my brothers served in uniform. I respect every one of our servicemembers. Donald Trump’s pick will make us less safe and must be rejected.”

Dan Meyer, a national security lawyer, argued that there have been previous secretaries of defense who had stellar resumes on paper but it didn’t translate to a successful tenure.

“Even the people who have the best of credentials for management and connections really struggle in that job,” Meyer explained. “For the most part, [the secretary of defense] isn’t dealing with all these people, [they’re] dealing with the 30 to 40 people that are closest to him in the ‘E ring,’” he said, in reference to the outer ring of the Pentagon where senior leaders’ offices are located.

Trump tapped Hegseth to lead the department because they share a similar view of what they believe has been the degradation of the military’s readiness and lethality due to what they describe as an overemphasis on diversity and inclusion, and it will be the former Fox News host’s job to reverse that trend.

Gene Moran, a national security expert, told the Washington Examiner, that “finding the right person, I think, has been the challenge for some time,” pointing out that there have been defense secretaries with experience leading a service branch who haven’t succeeded in the role.

“Running the Pentagon is really the job of the deputy,” he added. “So with a strong deputy that problem could resolve itself, with a strong policy person, he might get good counsel on the international relations aspect of the job. I think it remains to be seen how much latitude will President Trump give any of these cabinet secretaries.”

He noted that Secretary of Defense Lloyd Austin and former Secretary of Defense Jim Mattis (who served during Trump’s first administration) required Congress to pass waivers for them to serve in the position due to the proximity of their retirement from active-duty military service.

“I don’t support the former four-star generals having been selected for that role, that’s great experience, but I think it’s the wrong kind of experience,” Moran, a former adviser to multiple Chairmen of the Joint Chiefs in the early 2000s, said. “And each of those, General Mattis, General Austin, I think, had significant challenges interfacing with the political arena for different reasons.”

The GOP has shown an openness to Hegseth’s nomination — as well as all of Trump’s picks, even some of the more shocking ones — while others have shared more skepticism.

It’s unclear how else exactly Hegseth could shake up the military, if he’s confirmed, though prior to being selected, he expressed his support for firing the Chairman of the Joint Chiefs of Staff, Gen. Charles Q. Brown and he called for women to be barred from combat roles in the military. The president-elect is reportedly considering creating a board of veterans to evaluate senior military leaders to determine whether they are “lacking in requisite leadership qualities,” according to the draft reviewed by the Wall Street Journal.

 “Who the f*** is this guy?” a defense industry lobbyist told Politico, adding that they had hoped for “someone who actually has an extensive background in defense. That would be a good start.”

Hegseth, if he’s confirmed, will come into the role with a military facing a number of pressing issues aside from those associated with cultural concerns. The U.S. has provided two allies, Israel and Ukraine, with billions of dollars of military aid for years, depleting U.S. military stockpiles, as the department attempted under the Biden administration to turn its attention to the growing threat posed by the Chinese Communist Party, which DoD has described as its “pacing challenge.”

Trump has indicated he would maintain support for Israel even though he hopes they wrap up their conflicts quickly, while he and surrogates on the campaign trail indicated they would limit or stop aid to Ukraine. The Biden administration has provided more than $60 billion of military equipment to Ukraine since the war began, and officials have signaled that they will try to get Ukraine the remaining roughly $5 billion that have already been allocated for the department to arm them.

Retired Rep. Mike Gallagher (R-WI) wrote in a Wall Street Journal op-ed this week that Hegseth, or whomever becomes the next secretary of defense, needs to “go to war on day one — not with China, Russia, or Iran but with the Pentagon bureaucracy,” because the department has “two years to prevent World War III.”

He argued in a recent interview on Fox News that Hegseth should look to: reduce the size of the civilian workforce, fix the Navy’s shipyards to build more maritime vessels, and increase production of critical munitions and long-range fires, which have been depleted by the wars in the Middle East and Europe.

Trump had a rocky relationship with senior Pentagon leaders during his first administration, and the friction he had with them and others have charted a different course of action this time around — instead he is appointing loyalists and believers in the agenda.

Officials within the department have held informal discussions about how they would respond if Trump gave them an unlawful order, which they would be compelled to disobey, according to CNN.