WASHINGTON — U.S. President Donald Trump issued an executive order Thursday changing the line of succession at the Pentagon, clarifying who would take charge of the Defense Department in case of an emergency.

The move is in line with actions taken by previous presidents, who have in the past moved roles up and down the line of succession depending on the individual filling the job.

The order of succession lays out who takes over when a defense secretary is removed or resigns. It is not representative of the chain of command, but does reflect who the president would prefer to take over in case of a departmental emergency that results in the loss of the top of the command structure.

The switch comes amid a broader series of changes at the Pentagon — including alterations at the Defense Business Board and the Defense Policy Board — that the incoming Biden transition team may look to quickly revert once it takes office.

The new order is as follows:

  • Deputy defense secretary
  • Secretaries of the Army, Navy and Air Force, in order of appointment
  • Undersecretary of defense for policy
  • Undersecretary of defense for intelligence and security
  • Chief management officer
  • Undersecretary of defense for acquisition and sustainment
  • Undersecretary of defense for research and engineering
  • Undersecretary of defense (comptroller)
  • Undersecretary of defense for personnel and readiness
  • Deputy undersecretary of defense for policy
  • Deputy undersecretary of defense for intelligence and security
  • Deputy undersecretary of defense for acquisition and sustainment
  • Deputy undersecretary of defense for research and engineering
  • Deputy undersecretary of defense (comptroller)
  • Deputy undersecretary of defense for personnel and readiness
  • A group consisting of the general counsel of the Defense Department, assistant secretaries of defense, director of cost assessment and program evaluation, director of operational test and evaluation, and chief information officer of the Defense Department, in order of appointment
  • Undersecretaries of the military departments, in order of appointment
  • Assistant secretaries of the military departments and general counsels of the military departments, in order of appointment.

The executive order replaces a similar executive order issued by President Barack Obama in March 2010, which in turn replaced one signed by President George W. Bush in December 2005, which in turn replaced one from President Bill Clinton in April 1996.

“This is something every administration in modern times undertakes, but the world would not have stopped rotating had POTUS forgotten to change this on his way out the door,” said Mackenzie Eaglen of the American Enterprise Institute. “The more interesting question to me is why Obama did it so soon after taking office, and Trump at the very last minute.”

The department guidance came alongside a similar change of succession order for the Office of Personnel Management — a move that appears to boost a Trump favorite, now slotted into a career service position, to take over OPM following the Biden transition, should an OPM political appointee not be confirmed by Jan. 20.

Notably, the move jumps the undersecretary of defense for policy from sixth in line to fifth, and the undersecretary of defense for intelligence from ninth in line to seventh. The shifts come at a time when those two jobs have been filled with individuals seen as loyalists to Trump — Anthony Tata and Ezra Cohen-Watnick, respectively — who were never confirmed by the Senate and are serving in an acting capacity.

However, those two jobs had listed as the No. 2 and No. 3 in the line of succession in the 2005 executive order, so the move returns to an order from 15 years ago. At the time, the placement of those undersecretaries so high up in the succession order was seen as a move by then-Secretary Donald Rumsfeld to put loyalists higher on the list.

Per the order, no one listed above who is currently serving in an acting capacity, which would include both Tata and Cohen-Watnick, can fill the role of defense secretary. But that comes with a caveat: “The President retains discretion, to the extent permitted by law, to depart from this order in designating an Acting Secretary.”

That caveat would cover Trump’s decision to replace Defense Secretary Mark Esper with acting Defense Secretary Christopher Miller, who came from outside the department, instead of promoting Deputy Secretary of Defense David Norquist.

Sue Gough, a Pentagon spokesperson, said the executive order was done to “reflect changes in senior Defense civilian positions per the fiscal 2017 and 2020 National Defense Authorization Acts, such as the splitting of the Under Secretary of Defense for Acquisition, Technology and Logistics position and responsibilities into the Under Secretary of Defense for Acquisition & Sustainment and the Under Secretary of Defense for Research & Engineering; the creation of the Chief Management Officer position; and the redesignation of the Under Secretary of Defense for Intelligence to the Under Secretary of Defense for Intelligence & Security.”

Among other changes: making the order of service secretaries based on seniority, and moving the acquisition offices farther down the line. (The 2010 order had the acquisition, technology and logistics undersecretary as No. 5 in the order; that office was split into Acquisition & Sustainment and Research & Engineering in 2017.) The 2010 order also did not account for the chief management officer, which was stood up in 2018.

Arnold Punaro, a former Senate Armed Services Committee staff director and retired Marine Corps general, said the move puts the succession order “pretty much to the way it used to be.” While the succession order could be changed by President-elect Joe Biden at any time, getting this order laid out is particularly important given it’s immediately ahead of the presidential transition, he added.

Punaro noted that the choice of Lloyd Austin, a retired Army general and U.S. Central Command head who will require a congressional waiver to take office, combined with a runoff election in Georgia that will determine control of the Senate, means the clock is ticking to get Austin in place for the Jan. 20 inauguration.

“The House Armed Services Committee will be involved, and the earliest the Senate Armed Services Committee could probably get a hearing cranked up in the week of Jan. 11 due to the need to organize the Senate after the runoff, so you have 10 days before Jan. 20 and they might have a hearing on the waiver and then for sure on the nomination,” he said. “Those are very tight timelines to have someone confirmed on Jan. 20, assuming the Senate will accommodate the practice that a new president gets his SecDef on Inauguration Day — which they should, since that is the other civilian in the chain of command.

“If Gen. Austin is not confirmed with a waiver by Jan. 20, then this is the document that will determine who is the acting secretary of defense — unless President Biden decides to supersede it under the [Vacancies] Act.”