In the middle of an Era, all wars are limited

Italians holding severed head of innocent civilian Addis Adaba 1937 

WWII's beginnings were in the very middle of the Era of High Modernity, at a time when its intellectual hegemony was at its highest.

As a result, the elites on both sides of WWII were in much closer agreement on how the world was and should be, than if the world's peoples was still engaging with a totally new era or just in the process of leaving a very old era : the end result was to make the world's biggest baddest war to a strictly limited war,  intellectually and emotionally.

So for example Churchill and his fellow elites of the countries possessing internal or external colonies (that meant countries like Denmark and Canada as well as the better known suspects) has plenty of reasons why they didn't want Italy brought to trial for the horrific mass murders it committed in Libya and Ethiopia.

What the Germans had done in Western Europe was unforgivable, and so they had to stand trial.

For they had massacred en masse white middle class civilized Europeans.

Just as white middle class civilized Europeans had always done, albeit only imtermittently, to dark uncivilized non-Europeans, middle class and working class alike, without ever seeing trial.

But if Italy was brought to trial for its colonial war crimes, Churchill and his ilk all wondered, where would it end but in the total collapse of all the European imperial efforts around the world.

And considering that small "i" imperialism of the big against the small, extending down into the non-human world, was the core philosophy of High Modernity, it meant the collapse of High Modernity itself.

Which indeed happened anyway - interestingly, almost the day after Churchill died....