Defense Secretary Jim Mattis' stunning resignation over deeply held policy differences with President Donald Trump on the Syria withdrawal and other issues set off speculation Friday at a demoralized Pentagon on who else might follow him out the door.
Mattis was in his Pentagon office Friday, but there was no immediate word from Defense Department officials on whether he had signed off on the formal withdrawal order that would go to U.S. Central Command, and then to Combined Joint Task Force-Operation Inherent Resolve, to set in motion the process of pulling an estimated 2,000 U.S. troops out of Syria.
Former Defense Secretary William Cohen, a close friend of Mattis, said the crisis of confidence the former general reached in Trump's leadership would cause others in the top echelon of the Defense Department to consider their own feelings on whether to continue serving a sometimes erratic commander-in-chief.
Cohen told CNN that he spoke Wednesday night on the phone with a "distraught" Mattis, who was struggling with the decision of whether to resign.
Mattis had opposed Trump on a range of other issues, Cohen said, but he had reached the "breaking point" when Trump announced Wednesday via Twitter that he was ordering the Syrian withdrawal.
"I called him at the Pentagon and told him -- 'tell me it's not true.' I can tell you he was distraught" over the withdrawal and what he felt would be a "betrayal" of coalition allies and local partnered forces in Syria, Cohen said.
"Jim Mattis could not accept that," said Cohen, a former Republican senator from Maine. Cohen recalled Mattis as saying, " 'I have never resigned from anything, I have carried the fight in every battle I have been in, but I cannot do this in the name of our country.' "
Others at the Pentagon now will have to make their own decisions on whether they "resign or do they stay," Cohen said. "When it comes to the point where you can no longer carry out his [Trump's] directives, it's time for you to step aside."
The immediate speculation at the Pentagon was on the status of Joint Chiefs Chairman Gen. Joseph Dunford, who has also had differences with Trump.
Dunford served under Mattis as a colonel in command of the 5th Marine Regiment in the 2003 invasion of Iraq, when Mattis commanded the 1st Marine Division. Together, they were the first two Marines to hold the top uniformed and top civilian posts at the Pentagon.
Dunford's term as Joint Chiefs chairman runs through next fall, but Trump earlier this month named Army Chief of Staff Gen. Mark Milley to succeed him. Dunford has given no indication yet as to whether he would step down early once Milley is confirmed by the Senate.
The choice of Milley was considered to be another factor in Mattis' break with Trump. Mattis had favored Air Force Chief of Staff Gen. David Goldfein to succeed Dunford.
Mattis' departure is expected to have an impact on the pace and direction of the Defense Department's efforts to meet the growing challenges posed by Russia and China, while also carrying out other worldwide commitments.
However, one of the main concerns voiced by members of Congress from both sides of the aisle was the effect of Mattis’ departure on the troops, whose respect he earned in four decades in uniform.
Rep. Adam Kinzinger, R-Illinois, an Air Force major who served in Iraq and Afghanistan, said on Twitter that Mattis' resignation "was an act of patriotism, standing for American principles above all else."
He added, "The military is absolutely devastated by this."
At a news conference Thursday, House Minority Leader Nancy Pelosi, D-California, diverted from discussing the government shutdown threat to state her concerns about Mattis' departure.
"I am shaken by the resignation of General Mattis," she said. "Our troops looked to him as a leader, and now he's leaving them. This is a very sad day for our country."
-- Richard Sisk can be reached at Richard.Sisk@Military.com.