Black-and-white thinkers truly believe they are all good and the other guy is all bad.

They would pass lie dectectors if you asked them if their torture was always justified and the other guys was always wrong.

The would pass if you asked them if they truly believed th atrocities they commit were forced upon them by the bad behavior of the other guy and therefore justified.

You can't reason with someone who cannot see the world for what it is, who hasn't developed in their reasoning and logic since age 12, who believe every bit of propaganda which fits that adolescent view of the world. Straw men, ad hominem attacks, changing the subject, magnifying insignificant facts, ignoring substantial facts, and accepting at face value any untruth which meets their agenda, using the ends to justify any means, all of those are a few of the ways they dodge accepting responsibility for their actions.

It ain't gonna happen.

Couple that with the related inability to admit they are ever wrong, and you have a well-defended adolescent ego unable to comprehend a real world, with all it's richness and anxiety.