Editor’s note: This story has been updated to include information from a Pentagon spokesperson.

Correction: A previous version of this story misidentified Karlin’s position.

WASHINGTON — Mara Karlin, who since this summer has performed the duties of Pentagon deputy under secretary of defense for policy, announced today she’s stepping down.

The announcement continues the revolving door of officials performing top policy roles within the Defense Department, amid Sen. Tommy Tuberville’s (R-AL) hold on Pentagon nominees. Tuberville ended his blockade last week for all but the highest-tier of roles still vacant — including the top policy job.

In late July, the administration nominated Derek Chollet, a former Pentagon official now serving in the State Department, to fill the top position, which has been empty since Colin Kahl left government earlier that month. Sasha Baker, the confirmed deputy undersecretary of defense for policy, has been performing that role on an acting basis. Chollet appeared before the Senate Armed Services committee for a hearing on his nomination in late September, but hasn’t been confirmed.

Karlin has worked across the Defense Department since President Joe Biden took office in 2021. In her current role, she focused on writing and then implementing the 2022 National Defense Strategy, which tagged China and Russia as America’s “pacing” and “acute” threats. She also helped shepherd the AUKUS agreement, a wide-ranging security pact with Australia and the United Kingdom.

“When you look at all these challenges that are happening around the world, it’s American leadership that is playing the outsized role,” Karlin told Defense News earlier this month at the Reagan National Defense Forum.

A spokesperson for Karlin said that after a “semester at sea” with family, she will transition to academia — a home for many who have worked in top Pentagon policy roles in the past, including Kahl. The spokesperson didn’t specify where she would move other than to say it would be an “academic team” working with “a cohort of students following an impactful tour in national security.”

Assistant Secretary of Defense for Homeland Defense and Hemispheric Affairs Melissa Dalton will step into Karlin’s job next week.

Noah Robertson is the Pentagon reporter at Defense News. He previously covered national security for the Christian Science Monitor. He holds a bachelor’s degree in English and government from the College of William & Mary in his hometown of Williamsburg, Virginia.

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