WASHINGTON — Former Secretary of Defense Ash Carter has accepted a new job at the Harvard Kennedy School, with a focus on strengthening ties between the Defense Department and the tech sector — perhaps the defining focus of his Pentagon career. 

Carter will serve as the Belfer professor of technology and global affairs and director of the Belfer Center for Science and International Affairs. The Belfer Center is essentially the Kennedy school's think tank, hosting regular events and publishing issue papers on national security and international relations issues.

Coming with the former secretary is Eric Rosenbach, a former Pentagon official who served as Carter's chief of staff. Rosenbach will become co-director at Belfer.

During his tenure as secretary, Carter became known for his focus on reaching out to the commercial technology sector, and the Belfer job appears to be designed to allow that focus to continue — right down to the use of one of Carter’s favorite phrases, referring to the Pentagon as a "five-sided box," which is used in the second line of the news release announcing the move.

Part of Carter’s focus will be to tap into the Boston tech culture, something he had previously attempted to do when he created a Boston-area hub for the Defense Innovation Unit Experimental, a pet creation for the then-secretary.

In an interview with Backchannel, Carter said Boston "does a good job of combining engineering and tech and biotech, with a long tradition of working for the public good. I want to continue to build bridges between the innovative community, the tech community, and public purposes."

Carter served as secretary of defense from 2015 until the end of the Obama administration. He previously served as acquisition head from 2009-2011, and deputy secretary from 2011 to 2013 . In addition to a number of other roles at the Pentagon, Carter served as a professor at Harvard earlier in his career.