Such things would be the influence of the Adversary, or Satan if you will. Men are allowed to choose for themselves if they will follow God or the other guy. If God were to stop them every time they tried to do something bad, then they wouldn't really have free choice and it would make God to be more like a tyrant.
(Tyranny isn't good or godlike. Tyranny is more of Satan's game, so God isn't going to do that). Evil people will do evil things, but they will get their just punishment in the end.
They are allowed freedom to act so that their punishment can be just. If God stopped them from acting in an evil fashion, then He couldn't really punish them for being evil, now could He? That would not be justice.
But what of the innocent who are being harmed by such acts? Such acts of cruel depravity bring sadness to all good people, even God, I would imagine. As good individuals ourselves, we can do our part and use our agency to try to put a stop to these horrors and to rescue the innocents.
This would be a good thing (stopping the horrors, helping the victims). As for God's part, He actually does a lot of things behind the scenes that you just don't know about to help the victims when He can without overriding the agency of others. Those who die in such vicious acts are saved in the kingdom of God where they can rest from the troubles of this mortal life.
In the grand scope of things, this mortality is but a fleeting moment. God looks at the larger picture and everything will work out for the best, despite all of Satan's best efforts to the contrary. Oh, and God will still help us, even in our fleeting moments, so don't let that thought get you down.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.