Sitting just feet away from Chuck Hagel's Pentagon office, Lippert is effectively his gatekeeper. Lippert juggles being "the fireman" on security issues of the day with helping develop longer-term strategies on national security policy. "It's a very difficult challenge, because the issues of the day, if you're not careful, will easily overrun the strategic," he says. Lippert ensures Hagel's directions are carried out, coordinating with senior Defense officials. "They're constantly asking you, 'Hey, what does the secretary think about X, Y, or Z?' " Lippert, 40, was previously assistant secretary of Defense for Asian and Pacific security affairs, and chief of staff for Obama's National Security Council after advising his presidential campaign. Lippert's relationship with Obama and Hagel stretches back to their Senate days. He managed then-Sen. Obama's work on the Foreign Relations Committee, and earlier served on the State and Foreign Operations Appropriations Subcommittee staff under Sen. Patrick Leahy, D-Vt. The Ohio native has a master's in international policy studies from Stanford University, where he was an undergraduate as well, and he studied Mandarin at Beijing University. Like his boss, Lippert has military experience. Serving as an intelligence officer for Naval Special Operations Forces, Lippert says, "gives you a deeper appreciation of the fact that, at the end of the day, what this place has to be about is the mission."