Once again, Canada is way ahead of the curve on this one. They do all of the above and add the following: Once you come back from serving, if you experience any issues from your service, we'll take care of you with euthanasia.

Honestly, I'm surprised they aren't trying to encourage whites to sign up (calling whites racist for being white is NOT a good recruitment tactic). They could send the recruited whites to some pointless war and if they don't die there, they can euthanize them when they get back. Get some use out of this new under class before killing them off.

Both the Soviets and the Nazis this this, to a limited extent. The Soviets were too good at the "starving them to death" part for them to get much useful work out of their gulag prisoners. Plus, good luck getting good work out of a feeble abused starving prisoner. You can't cut his rations because you already feed him basically nothing. And you can't beat him into submission or he'll basically just die due to how weak he is. Tortured and starved prisoners just aren't that motivated nor do they have the strength to do much work.