Of the 43 U. S. Presidents, only 11 did not serve in the military.
74.4 % of U S Presidents wore the uniform. (32)
72 % were officers. (31)
56 % served in a command capacity. (LTCmndr/Major and above) (24)
56 % served during war time. (24)
I think the numbers speak for themselves.
http://en.wikipedia.org/wiki/List_of..._military_rank
http://www.whitehouse.gov/history/presidents/