WASHINGTON — Defense Secretary Lloyd Austin directed the military on Thursday to carry out a smooth transition to President-elect Donald Trump, with a reminder to the force of its obligation to follow the lawful orders of the next commander-in-chief.

Defense Secretary Lloyd Austin smiles during a joint press briefing with South Korean Defense Minister Kim Yong Hyun at the Pentagon on Oct. 30 in Washington. Kevin Wolf/Associated Press file

While such memos are rare, it was not the first time the military’s top civilian leader has pressed the force on its duty to the Constitution in regard to a changeover of control under Trump.

However, in the context of the incoming president’s suggestion that he may use federal forces at the southern border, and Project 2025 plans to force out career civilians and fill positions with Trump loyalists, the Biden administration has taken unusual steps both to try to insulate those civil servants and to remind the military of its own sworn oaths.

“As it always has, the U.S. military will stand ready to carry out the policy choices of its next Commander in Chief, and to obey all lawful orders from its civilian chain of command,” Austin wrote in his letter to Defense Department personnel.

“The U.S. military will also continue to stand apart from the political arena; to stand guard over our republic with principle and professionalism; and to stand together with the valued allies and partners who deepen our security,” he wrote.

Austin reminded all members of the military that they swore an oath to support and defend the Constitution – “and that is precisely what you will continue to do.”

In 2016, the outgoing defense secretary in the Obama administration, Ash Carter, also pressed for an orderly transition after Trump was elected, telling the force he knew it would continue in the tradition of excellence “our citizens know they can expect.”

When Trump’s Defense Secretary Jim Mattis resigned in 2018, he urged the force to remain “undistracted from our sworn mission to support and defend the Constitution.”

“Our Department is proven to be at its best when times are most difficult,” Mattis wrote in December 2018, after resigning due to disagreements with Trump over a withdrawal of troops in Syria.

After the Biden administration, through the Office of Professional Management, issued a new rule in April to further insulate career civil servants from being involuntarily replaced by political appointees, Austin reiterated the Pentagon’s commitment to do the same. In a letter dated July 10, he said civil servants would be shielded “from unlawful or other inappropriate political encroachments.”

The regulations were in response to an executive order Trump issued in 2020 that sought to allow for reclassifying tens of thousands of the 2.2 million federal employees and thus reduce their job security protections, which is expected to re-emerge in the second Trump term. It is unclear what sort of protections that workforce will still have in a new administration, particularly if Trump issues an executive order undoing the protections put in place for those civilian workers under President Biden.