It appears that president-elect Donald Trump is very interested in the prospect of having retired Marine General James “Mad Dog” Mattis serve as Secretary of Defense. There is one small hitch in the process though, a law preventing former military members of serving as Secretary of Defense within seven years after they have left active duty. Warontherocks.com explains:
Articles assessing the Mattis prospect have been numerous and mostly quite positive (see, for example, Eli Lake’s roundup of positive reviews from across the political spectrum). As many of those same articles also note, however, there is a catch: 10 U.S. Code section 113(a), which provides in relevant part that a “person may not be appointed as Secretary of Defense within seven years after relief from active duty as a commissioned officer of a regular component of an armed force.” (The National Security Act of 1947 originated this limitation, and from 1947 to 2008 the waiting period actually lasted ten years rather than just seven). Because Mattis retired in May 2013, the statute plainly bars him from serving as secretary of defense until May 2020. So why still talk him up as a prospect? There is a good answer, but it is a bit more complicated than some of the coverage has suggested.
Many of the Mattis-tracking articles note this problem, but suggest that it can be overcome with a “waiver” from Congress. That’s accurate at bottom, but “waiver” sure is an awkward way to describe what actually would have to happen: For Mattis to be secretary of defense, it will require a new statute, one that either carves out a case-specific exemption for him or repeals this aspect of section 113(a) altogether. That is, either the lame-duck Congress and President Obama will have to act affirmatively to make this happen, or else it will have to wait till the new Congress and President Trump can get to it post-inauguration.
It certainly can be done. It has been done, in fact, once before. In September 1950, President Truman wanted to appoint George Marshall as secretary of defense despite the ban and went to Congress to get a statute that would override the National Security Act just in this instance. In the end, he got it but not without a bit of anxiety regarding the principle of civilian control of the military.