Patrick M. Shanahan speaks to members of the Military Reporters and Editors Association during their annual convention at the Navy League Building in Arlington, Va. in October.

Patrick M. Shanahan speaks to members of the Military Reporters and Editors Association during their annual convention at the Navy League Building in Arlington, Va. in October. Sgt. Amber I. Smith/Defense Department

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Can Pat Shanahan Serve as ‘Acting’ Defense Secretary Forever?

The law is unclear, and the situation all but unprecedented.

“Indefinitely” is how long the Trump administration contends that Deputy Defense Secretary Patrick Shanahan can fill the role of his departed boss, Jim Mattis. President Trump has said he is in “no hurry” to replace Shanahan and his numerous fellow acting cabinet secretaries, telling reporters Sunday that “I sort of like ‘acting’” because “it gives me more flexibility.”

But Shanahan could face legal challenges if he stays in the position too long, some scholars say. The situation is all but unprecedented: There have only been two acting defense secretaries in the 71 years since the role was created. Although there is little debate that the deputy secretary is the most appropriate person to fill in until the Senate can confirm a replacement for Mattis, there is a fierce debate over what time limits — if any — the administration faces to nominate that person.

The key law governing the rules of succession at the Pentagon is the 1986 Goldwater-Nichols Act, which reshaped the Department’s command structure. Goldwater-Nichols stipulates that when the secretary’s position becomes vacant, the deputy secretary exercises the full powers of the secretary. The law does not set a time limit on how long he can do so, and it makes clear that there are no limits on the inherent authorities of the job when it is exercised by the deputy in an acting capacity, according to Arnold L. Punaro, a retired two-star Marine general who helped draft the law.

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“No one should consider Pat Shanahan as a ‘caretaker’ or ‘hampered’ by the term ‘acting,’” Punaro said in an email. “He is as we say in the Marine Corps, a ‘full-up round.’”

But Punaro has also said that the law’s architects never intended for anyone to fill the role indefinitely.

There is a separate piece of U.S. law — known as the Federal Vacancies Reform Act — that does include a time limit. But legal scholars say it doesn’t appear to apply to the Defense Department, whose succession Congress specifically addressed in Goldwater-Nichols. Steve Vladeck, a national-security law professor at the University of Texas, notes that it’s possible, yet “unpersuasive,” to argue that the Vacancies Act is meant to complement all agency succession statutes.

A more open question, according to Vladeck and others, is whether the Constitution limits Shanahan’s time as acting secretary.

Under the appointments clause, Cabinet officials must be nominated “by and with the advice and consent of the Senate.” Some scholars — like Marty Lederman, a former deputy assistant attorney general in the Department of Justice’s Office of Legal Counsel — believe this condition has already been met, because Shanahan was confirmed by the Senate to serve as the deputy secretary, and he is now exercising the authority of that role as envisioned by Congress in Goldwater-Nichols.

“No time limit under the statute or the Constitution — Shanahan is performing the functions for which the Senate confirmed him as Deputy,” Lederman tweeted.

But Vladeck argues that the Constitution imposes “some kind of reasonable constraint” on Shanahan’s tenure as secretary — although it’s not clear how long. Vladeck notes a footnote in a 2017 Supreme Court case that found a person nominated for a position cannot hold the same job on an acting basis while awaiting Senate confirmation: In his concurring opinion, Justice Clarence Thomas called the “temporary” appointment of the acting general counsel of the National Labor Relations Board a “trivial distinction” under the Appointments Clause, specifically homing in on the length of time that he spent in the post in that capacity. Lafe Solomon served for more than three years in an office limited by statute to a four-year term, according to Thomas’s opinion, and “he exercised all of the statutory duties of that office.”

“We’re not in uncharted territory yet,” Vladeck said. “I don’t think there’s any serious argument against him serving until at least the six-month mark.”

But right now, there’s little signal that Trump is moving quickly to replace Mattis. He has said Shanahan “could be there for a long time” and on Friday, shot down a New York Times report that he was considering nominating one-term Democratic senator and former Navy Secretary Jim Webb. Last week, a U.S. official told reporters that Shanahan could serve in the post for “an indefinite period at the discretion and direction of the president,” although the official acknowledged that the situation was “nebulous.”

Any practical challenge to Shanahan’s ability to continue to serve in the post beyond a certain timeframe would likely have to come from someone directly affected by an order he signs or a contract he approves. That person or entity might be able to bring a legal challenge on the grounds that Shanahan lacks the legal authority of the defense secretary.

Still, Shanahan’s case is different both in substance and politics from the appointment of Matt Whitaker, former Attorney General Jeff Sessions’ chief of staff who now fills the top post at the Justice Department in an acting capacity. Whitaker’s appointment sparked a maelstrom of criticism over the validity of the appointment under both the Appointments Clause and the Vacancies Act. Much of the legal questions about Whitaker don’t apply to Shanahan because Whitaker, as Sessions’ chief of staff, was not in the legal line of succession nor had he been confirmed by the Senate in any post.

Whitaker is also a far more controversial figure. Although Shanahan lacks any prior government or legislative experience, he is seen as a competent technocrat and was confirmed 92-7 as deputy.

“In some ways, Shanahan is a more neutral case for how we feel about actings,” Vladeck said. For now, the question is merely whether Trump will move in the coming months to appoint a permanent replacement.

“I think this is all just academic right now.”