As deputy staff director and general counsel to the House Armed Services Committee, Roger Zakheim has been on the front lines of hot-button national security and defense issues over the past year, advising the Republican-led committee on everything from the drawdown of troops in Afghanistan to defense budget cuts.

Zakheim turned 35 in August, but his influence already stretches beyond Capitol Hill. Last October, he was tapped to be part of GOP presumptive presidential nominee Mitt Romney’s national security and foreign policy advisory team, serving as co-chair of the defense working group. It was a testament to his expertise: The other co-chair is John Lehman, a former Secretary of the Navy in the 1980s and member of the 9/11 Commission.

“He’s a very smart guy and has an in-depth knowledge of defense and national security issues that is not commensurate with his age,” said Robert O’Brien, managing partner of Arent Fox’s Los Angeles office, who serves as a senior Romney adviser and co-chair of the campaign’s international organizations working group. “This guy can go toe-to-toe, number-for-number, weapons platform-by-weapons platform with anyone who is out there.”

Zakheim, who declined to comment, joined the committee in 2005 after earning his J.D. from New York University School of Law. National security and defense work runs in his blood — his father, Dov Zakheim, is a former high-level U.S. Department of Defense official and is also an adviser to the Romney campaign, on national security and defense issues.

In 2008, Roger Zakheim left the committee to become a deputy assistant secretary of defense. He rejoined the committee the following year and became deputy staff director and general counsel in January 2011.

Zakheim wears two hats in his current job, managing the committee and advising on legal issues. “He is a first-rate attorney, hard worker and considered to be an honest broker,” said Paul Lewis, the Armed Services Committee’s minority general counsel.

Zakheim has been an important force behind committee Chairman Howard “Buck” McKeon’s (R-Calif.) opposition to defense budget cuts. In evaluating detainee policy, another issue at the top of the agenda, O’Brien said Zakheim’s background allows him to consider the issue from all sides, from national security to due process. “What I see with Roger are the skills that I’d associate with the better litigators,” he said. “He’s got an ability to take a complex issue and get to the heart of the matter very quickly.” — Zoe Tillman