To be fair, a lot of the blonde, blue-eyed Aryan 12-year olds were volunteering to die for the fatherland, because by that time, they had been indoctrinated for years. You can teach people to "enjoy being instrumentalized" for the cause.
The world was lucky in the end that the Nazis sacrificed their young so young, instead of having the next generation gain the power to sacrifice the world in their own turn.
@Yendolosch @cstross
I'm not sure you can describe that as volunteering.
Legally speaking, 12 year olds are not capable of giving consent.