The Department of Defense’s chief of staff Rear Adm. Kevin Sweeney has resigned, sending more shock waves through the defense department.
Sweeney said in a brief statement that he planned to return to the private sector, giving no reason for his departure.
His exit comes just days after Secretary of Defense James Mattis, for whom Sweeney previously served, left the agency after announcing his resignation earlier in the month.
“After two years in the Pentagon, I’ve decided the time is right to return to the private sector. It has been an honor to serve again alongside the men and women of the Department of Defense,” Sweeney said in his announcement.
His resignation also followed that of another top Mattis ally, Pentagon spokeswoman Dana White, who announced her resignation at the end of December.
“I appreciate the opportunity afforded to me by this administration to serve alongside Secretary Mattis, our Service members and all the civilians who support them. It has been my honor and privilege,” White wrote on Twitter last month. “Stay safe and God bless.”
News of the Mattis resignation sent chills through halls of the Pentagon, where he had been a calming influence amid the constant tumult of the Trump presidency.
The retired four-star Marine Corps general had spent the last 23 months of his tenure trying to thread the needle between implementing Trump’s policy objectives and maintaining long-standing American principles.
Mattis’s resignation was thought to be tied to the surprise announcement from Trump regarding the withdrawal of U.S. troops from Syria, where coalition forces continue to battle elements of the Islamic State on the ground.
Trump’s withdrawal of U.S. forces from Syria was also credited at the time with pushing the resignation of Brett McGurk, the president’s top envoy to anti-ISIS coalition forces in the region.
Mattis’s candid resignation letter criticized Trump’s attempt at warming relations with China and Russia, two nations Mattis referred to as “authoritarian” regimes that promote “their own interests at the expense of their neighbors, America and our allies.”
Astonishment has become a familiar sentiment at the Pentagon under Trump.
New policy declarations, often made via Twitter, have caught military brass flat-footed: the withdrawal from Syria, the transgender troop ban, a proposal for a massive military parade and the decision to send thousands of active duty troops to the U.S.-Mexico border.
At a White House cabinet meeting Wednesday, Trump criticized Mattis’ handling of the Afghanistan war, which he said was “not too good” despite additional funding and manpower commitments.
“What’s he done for me? How has he done in Afghanistan? Not too good. Not too good. I’m not happy with what he’s done in Afghanistan and I shouldn’t be happy,” Trump said.
Acrimony between Trump and prominent former military leaders has spilled into the open in the wake of Mattis’ resignation.
Former Army Gen. Stanley McChrystal, who commanded U.S. forces in Afghanistan from 2009 to 2010, called Trump “immoral” and unfit to lead, to which Trump responded that McChrystal had a “big, dumb mouth.”
Trump also went after the “failed generals” who oversaw American wars in Iraq and Afghanistan, likely referring Gen. David Petraeus, a former CIA director under former President Barack Obama, and Adm. William McRaven, a Navy SEAL who oversaw the operation to kill Osama bin Laden.
Both men have publicly criticized Trump’s national security decisions and his temperament in recent weeks.
Mattis’s former deputy, Patrick Shanahan, began serving as acting Defense secretary at the beginning of January.