I work with a guy who got injured in Iraq, and was reassigned to a medical holding unit stateside while the army figured out if they could fix his back. The psychological and physical trauma soldiers go through is astounding. He told me of one guy, the lone survivor of a Bradley Fighting Vehicle that had hit a Russian anti-tank mine. He had a severe traumatic brain injury and would open imaginary doors and try to step through them. There's no fixing a brain injury like that.
There are tens of thousands of people who are a shell of their former selves.
There better be an extremely good reason to go to war.