Actually, the United States Marine Corps HAS come up with a martial art that is based on the concept of the fighting Marine, armed as they are, going into combat.
http://en.wikipedia.org/wiki/Marine_Corps_Martial_Arts_ProgramI reviewed their basic manual, which provides an overview of the skills needed to attain their most basic required belt level to graduate boot camp. (Tan Belt)
Folks... this is the real deal... stripped down to the bare essentials. Absolutely ROCK solid, and simple stuff.
I'll be keeping my eyes peeled for the curriculum overviews on the other belt levels, to be sure. I could see real fast where a 'straight to the point' program like this, if modified appropriately, COULD serve as a basis for a solid defense program for civilians through martial arts schools. (Obviously citizens don't carry an M16A2 service rifle with fixed bayonet!)
It's definitely a great system from what I've read of it.