it is not a military dictatorship in that, though the commander in chief is in charge of the military, he is for all intents and purposed an elected civilian with the power to direct the military.
i might be mistaken, but i believe that he holds no military rank and has less top secret clearance than some in the military.
it is also not the military which is policing the united states, though that has become a danger with some of the provisions of the patriot act.