Russians are lining up to go to war under the promise of money, around 30k a month last time I checked. Americans not so much, in particular not against Europeans. It's different in my view.
And also, our whole military recruitment strategy here outside of drafts has been "the GI bill" – paid tuition in exchange for lining up to go to war.
I don't know that the gap in morals is as wide as you think.
Which historically has worked more for us, than against us.
Russians are much, much worse than Americans in terms of their eagerness to kill others, in my opinion. I wish it were not so.