On Monday, President Trump announced via Twitter that Christopher C. Miller would assume the role of Acting Secretary of Defense, following the termination of Mark Esper.

The news didn’t come as a surprise to many, as whispers of Esper’s likely departure had gained traction throughout last week’s hectic coverage of the 2020 presidential election. For days, rumors circulated that Esper had prepared a letter of resignation, only for Pentagon officials to dismiss those rumors days ago. Now, it seems the rumors were likely true as President Trump announced Esper’s dismissal on Twitter using the word “terminated.” The president did, however, thank Esper for his service.

According to President Trump, Christopher C. Miller will immediately take on the role of Active SECDEF (Secretary of Defense), granting him little turnover with the outgoing Esper. Miller previously served as the Assistant Secretary of Defense for Special Operations and Low Intensity Conflict, where he was responsible for overseeing a wide variety of special operations missions. Prior to that role, Miller served in the U.S. Army — first as an enlisted infantryman, before earning his commission in 1987. He later went on to serve as a Military Police Officer in the District of Columbia National Guard before transferring to Special Forces in 1993. From there, he served in a number of command and staff positions within the 5th Special Forces Group (Airborne).

Miller had participated in the initial combat operations in Afghanistan in 2001 and Iraq in 2003 and completed several deployments to both theaters in the years that followed. During that time, Miller accrued what the Pentagon has characterized as “extensive inter-agency and joint special operations experience.”