Reinstate the draft.
That might seem counterintuitive since that would give us a lot more soldiers to use, but it would give a lot of families, a lot of Americans real skin in the game.
Wasting soldiers is easy as long as most people dont care and dont notice. But when it is your daughter/cousin/ uncle/parent someone you know for a majority of the population it becomes a very serious matter.
I say this as an ex-army soldier. I will be honest and say that I didnt enjoy my time in the military very much, and forcing thousands and thousands of youth to go through it means a lot of pain and uncomfortable situation, I think the benefits would outweigh the sacrifices made to make this happen.
An alternate plan would it to be mandatory that family members of elected officials to serve in the military and in wars, personally. (Not just sit at a desk in DC pushing buttons) But there is so much corruption in those systems that the children would probably be protected one way or another.