Yes, it's just that optimizing the force for a domestic purpose does somewhat reduce the recruiting pool.

I get what you are saying but even in the military this is not always a good thing. I had to fight/escalate many times when people gave very poorly thought through orders. They don't like my kind, but if none of us are left to rock the boat I could foresee monumentally dumb things occurring that could harm many military and civilian alike and waste vast amounts of taxpayer money.