https://www.grossmanacademy.com/about-the-colonel
I read a couple of his books years ago. He said one of the effective ways to desensitize a soldier to killing is violent video games. He’s studied violence his entire career, unfortunately not enough people seem to listen to him. I think being in the military and studying how to desensitize people to violence and then reintegrate them back into a peaceful society has given him a unique perspective. But like many people who really seem to have a handle on the cause and effect of things he’s largely ignored.