Eric Chewning will step down as chief of staff to Defense Secretary Mark Esper at the end of January to return to private sector work. Photo by U.S. Chamber of Commerce
Jan. 6 (UPI) -- Defense Secretary Mark Esper announced Monday that his chief of staff Eric Chewning will step down at the end of the month to return to the private sector amid mounting tensions with Iran.
Jen Stewart, minority staff director for the House Armed Services Committee, will replace him.
"I'm grateful for Eric's professionalism, judgment and leadership over the last seven months as I moved into the Secretary of Defense role," Esper told Defense News. "In an incredibly demanding job, Eric has been a source of calm and tireless work. We wish him all the best upon his return to the private sector."
The departure comes amid U.S.-Iran tensions after the U.S. military killed Iranian Gen. Qassem Soleimani in an airstrike.
John Bass, who has served as U.S. ambassador to neighboring Afghanistan since December 2017, also announced his departure Monday, though the State Department said the move as part of the "normal rotation cycle" for diplomats.
Chewning left a job at Morgan Stanley to enlist in the U.S. Army following the 9/11 terrorist attacks and later became commissioned as an Army intelligence officer. He returned to the private sector as a partner at McKinsey & Co. prior to joining the Pentagon, where he served as head of the Pentagon's industrial base office in October 2017, helping to oversee a White House-ordered review of the defense-industrial base.
Last January, he served as chief of staff to then-acting Defense Secretary Pat Shanahan, and he remained in the role when Esper took over in July. Esper replaced Jim Mattis, who resigned in December 2018 after President Donald Trump's surprise decision for a "full" and "rapid" withdraw of U.S. troops from Syria.
Chewning was involved in recently released unredacted emails that showed Pentagon officials were concerned with the legality of holding up military assistance to Ukraine over the summer, a central issue in Trump's impeachment.
In late August, Chewning relayed to acting Pentagon comptroller Elaine McCusker defense contractor L3Harris Technologies questions about the status of Ukraine funding in the emails reported by Just Security. McCusker criticized the Office of Management and Budget for saying the freeze wouldn't prevent full spending of aid.
Chewning wrote a memo to OMB warning that the Ukraine aid was in danger of not being fully spent by the end of the fiscal year and would have to wait until after a September meeting between Vice President Mike Pence and Ukrainian President Volodymyr Zelensky in Poland.
"We expect the issue to get resolved then," Chewning wrote to McCusker. "If not, I think we need to send the letter."
Chewning's departure is the sixth high-profile exit from the Pentagon in a month. Other recent high-profile exits include the senior adviser for international cooperation, the director of Defense Advanced Research Projects Agency, the acting undersecretary for personnel and readiness, the principal deputy undersecretary for intelligence and the assistant secretary for Asian and Pacific security affairs.
Chewning's replacement, Stewart, has led the Republican staff on the House Armed Services Committee since 2017.
Before the Democratic Party took over a majority of the House, she was also a national security adviser to then-House Speakers Paul Ryan, R-Wis., and John Boehner, R-Ohio.
"I have known Jen for years, and I'm excited to bring her into the department," Esper said. "Her deep expertise on national security issues will be a great addition to our team as we continue implementing the National Defense Strategy."