why didn't they just start WW3 to kill even more white men
Lol, be careful what you wish for!
But, to answer your question; why would you want to murder all the slaves you force to do your work? And in this case, to make the situation even more preposterous - if nuclear “doomsday” weapons existed and all the fear porn propaganda about them absolutely true; even if you should want, for whatever reason, to kill all the whites - you would make the world, that you need, unlivable and the food poisonous if you used them to get the job done...
Lol, be careful what you wish for!
But, to answer your question; why would you want to murder all the slaves you force to do your work? And in this case, to make the situation even more preposterous - if nuclear “doomsday” weapons existed and all the fear porn propaganda about them absolutely true; even if you should want, for whatever reason, to kill all the whites - you would make the world, that you need, unlivable and the food poisonous if you used them to get the job done...