WASHINGTON — Regular delays in nominations, combined with significant turnover at the highest levels of the Pentagon, means 40 percent of the top jobs at the department that require Senate confirmation are without an approved appointee as the Trump administration winds down.

A tally by Defense News shows 24 of the 60 positions at the Department of Defense are not occupied by confirmed individuals, with experts seeing little chance any current nominees will receive Senate approval before the clock runs out.

Among those offices without a confirmed official are some of the top civilian roles in the department: the Secretary of Defense and the undersecretaries of intelligence, policy, research and engineering and the comptroller.

Almost all of the vacancies are within the Office of the Secretary of Defense (OSD), while four spots —Undersecretary of the Navy, Undersecretary of the Air Force, Assistant Secretary of the Air Force for Space Acquisition and Integration, and General Counsel of the Army — are vacant at the service level.

The high-profile firings of Defense Secretary Mark Esper, USD-Policy James Anderson and USD-Intelligence Joseph Kernan last week contributed to the empty seats in the department. But the vacancies have been an issue all year — twenty seats were open in April — and the administration has been generally slow to fill spots.

According to information compiled by Arnold Punaro, a former Senate Armed Services Committee staff director and retired Marine Corps general officer, the Trump administration has lagged dramatically behind its predecessor in getting defense officials confirmed.

It took the Obama administration an average of around 5 months to nominate and just over 2 months to confirm its Presidential Appointments requiring Senate confirmation, or PAS, officials — an average of a 7 month process, according to Punaro’s data. Top-tier OSD officials, such as an undersecretary for policy, took just under four months to confirm.

But the Trump administration was plagued by a slow process for identifying and nominating individuals for top spots. It took around 7.5 months to nominate and almost 3.5 months to confirm — an average total of 11 months to confirm such individuals. When it comes to those top-tier OSD officials, it took the Trump team six months to nominate and an additional three months to confirm, over twice as long as it took the Obama team for those same roles.

Similar data compiled by the White House Transition Project show that the Trump administration lagged behind every administration back to Ronald Reagan in nominating and confirming appointees.

The following roles all currently lack a Senate-confirmed appointee:

All of those roles, except the deputy comptroller, have individuals filling the job in either an acting or performing-the-duties-of capacity, which come with slightly different rules. In some cases, officials have been filling those roles for most of the year.

Of that list, 11 have announced nominees in various states of the process, including Scott O’Grady, an Air Force veteran who was announced as Trump’s nominee on Monday to be ASD for international security affairs. But those nominees, including some who began the process in March, shouldn’t hold out hope for taking office, Punaro said. (No confirmation hearings are currently scheduled for the Senate Armed Services Committee.)

“The clock was bad for those nominees in July. Now, the clock is broken,” he said, noting that there are really only about 14 working days left for a Senate that is already roiled by claims of election fraud and a runoff campaign in Georgia that will determine control of the chamber. Meanwhile, Senate Majority Leader Mitch McConnell is likely to focus on appointing judges who will outlast the administration.

“Regrettably, I’m not real optimistic that those on the calendar or in front of the committee have a realistic shot of moving in the waning days of the lame duck,” Punaro said.

As to why the administration has struggled to get nominees through quickly, Virginia Sen. Tim Kaine, the top Democrat on the SASC Readiness and Management Support Subcommittee, said the quality of candidate has been a problem.

“There’s a lot of reasons for these vacancies: Trump is chasing people away or people have left, and then Trump is sending up people who are not confirmable by the Republican majority,” Kaine told Defense News in a Friday interview. “Trump has really kind of liked the ‘actings’ and the temporaries who don’t go through Senate confirmation because [they don’t] have to participate with Senate oversight ... and that’s a strategy bigger the Defense Department.”

That can be seen most obviously in the case of Anthony Tata, currently performing the duties of the USD-Policy after his Senate confirmation was scrapped this summer.

Quantifying the impact of these spots being open is difficult, said Mackenzie Eaglen, a defense expert with the American Enterprise Institute.

“This administration has chronically under-filled senior political positions in the Pentagon so the bureaucracy has adjusted to some extent,” she said. “At the same time, there are certain high-priority issues that cannot advance past a certain point absent a senior official with Senate confirmation pushing it forward. It’s as if there are invisible goal posts that bound the behavior and options available to career civil servants.”

Punaro agreed that civil servants, as well as uniformed officers, can pick up some of the slack, adding that with just two months of the lame duck term left, the lack of confirmed leadership shouldn’t be much of a problem.

But one aspect of lacking those top confirmed civilians is of clear concern to Eaglen: the civ-mil balance of power.

“There is a marked decline in civilian influence, expertise and relevance inside the Pentagon while power is increasingly consolidated in the Joint Staff,” she said. “The impotence of OSD will have to be addressed by the next administration before this issue gets so bad as to be irredeemable.”

Joe Gould in Washington contributed to this report.

Aaron Mehta was deputy editor and senior Pentagon correspondent for Defense News, covering policy, strategy and acquisition at the highest levels of the Defense Department and its international partners.

More In Pentagon