In December, Randall Schriver, the assistant secretary of defense for Indo-Pacific affairs, resigned. In January, Eric Chewning, Mr. Esper’s chief of staff, followed suit. In February, the president fired Mr. Rood, who was part of the Pentagon team that told Congress that Ukraine had made the necessary changes to justify sending the country $250 million in promised security assistance. The certification undermined a key argument that Mr. Trump’s defense team made during his impeachment battle: that Mr. Trump withheld the aid because he was concerned about corruption in Ukraine.
In April, the acting Navy secretary, Thomas B. Modly, resigned after his efforts to appease Mr. Trump resulted in a bungled Navy response to a coronavirus outbreak aboard the aircraft carrier Theodore Roosevelt, engulfing the Navy in a command crisis and a public relations disaster.
And this month, the resignation of Ms. McCusker continued the fallout from the Ukraine affair — the same affair which has now brought Colonel Vindman to the possible edge of departure if his promotion falls through.
As the Pentagon wrestles with high-profile resignations in its front office, the sprawling bureaucracy is also contending with leadership failures in some of its smaller departments.
Earlier this weeks, employees from the Defense Digital Service, a small Pentagon office that uses Silicon Valley technology on major military issues, sent an anonymous email to Mr. Esper highlighting longstanding issues within their office, where roughly 50 people work.
“Cultivated by both our director and deputy director, the toxic environment within D.D.S. has bubbled over,” the email, that was also sent to reporters, read. “This has resulted in a group of us consisting of minorities, both men and women of color Asian descent who feel silenced professionally and now morally.”
Launched in 2015, the Defense Digital Service is helmed by Brett Goldstein, who was appointed to the job in 2019. He has been the subject of several internal complaints and has drawn scrutiny from lawmakers. Before the Pentagon, he helped develop the popular dining system OpenTable and was directly involved in creating predictive policing software.