One reason is that civilians have ultimate authority over the armed forces, although generals have become President many times.
Another is that there is so much money to be made in the military and the surrounding defense contractors, and in the modern day glory with violence and conquering is less pleasurable than big houses and luxury cars.
Another is that there is so much money to be made in the military and the surrounding defense contractors, and in the modern day glory with violence and conquering is less pleasurable than big houses and luxury cars.