More than 20 percent of the 53 senior political appointee positions across the pentagon are either vacant or staffed with acting personnel. Among the jobs that require Senate confirmation, there are currently 11 filled byacting personnel, some for more than a year or longer. And with Assistant Secretary of Defense for Asian and Pacific Security Affairs Mark Lippert moving become the special assistant to Defense Secretary Chuck Hagel, the number of positions staffed by acting personnel will soon be 12.

And, another two positions -- the assistant secretary of the Air Force for acquisition, and the principal deputy undersecretary of defense for personnel and readiness -- are simply vacant.

It's not unlike the State Department, where  a number of key jobs are vacant -- or, for that matter, a number of other agencies across government, from Commerce to NOAA. "It's a problem that ebbs and flows," CSIS says , noting that the number of Senate-confirmed positions in the Pentagon was 46 underBush 41 -- now it's 53, a 15  percent increase. "That's not enormous, but it's a pretty big number," he said.

With each job, it's a question of getting the White House to put a name forward, then getting through the hearing process, and then getting full Senate confirmation. Currently, Senate staffers say that there is only on nominee awaiting confirmation by the Senate: Alan Estevez, to be principal deputy under secretary of defense for acquisition, technology and logistics. No one has been yet nominated by the White House for any jobs since Hagel arrived at the Pentagon. But Berteau notes that when there is new leadership, the already-slow process slows even more. "You do have the dynamic when a John Kerry or a Chuck Hagel come in, you'll slow up the
nominating process," he said. They ask themselves, "Who do need, who do I got, where do I get to pick from?"

For now, the number of vacancies poses a governance challenge for Hagel, Berteau said.

"There is little doubt that acting officials do not pursue the policy objectives of the administration with the same vigor, and commitment that a confirmed official does, in general."

Insiders say  Hagel is working to ensure that as many positions are filled as soon as possible with Senate-confirmed appointees but that he is confident their missions are
being carried out "responsibly and effectively" in the meantime. "Some of those in acting roles might eventually hold those positions permanently," the official said. "All of this requires, of course, the partnership of Congress."