Personally, I've come to the conclusion that anyone who has the capacity and wisdom to know why wars are waged in the first place would never voluntarily fight in one.
It's reinforced my philosophical idea that wars are just a way for humanity to purge the worst of itself.
Defending Your hoke is poorly the only way a human can cooe with horrors of war and not come out completely broken.
Being on the invading side is essentially signing for life time of ment issues since there is no good way to cope besides openly saying yeah I like going to other countries to kill people for money...