As hard as his situation is, he's going to have to learn to live with it. You want to be helpful, but you can't help him by allowing him to be weak. Next time you see him, just say, "Look.
I thought you were joking. You need to get over the fact that I didn't understand. I want to help you, but I'm not going to help you if you're being a jerk to me.
So let's get over this and we'll keep moving." Then, he can get tough and you can start talking about the issue. And the solution, again, not easy but necessary, is that he's going to have to accept that it happened and then get stronger than it is.
Allowing him to stay weak is only making things worse.
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.