The military actively seeks out certain people to do special jobs such as snipers and socom. There’s a not small portion of the population that given the change enjoy inflicting pain and killing other humans it’s just a fact some people are programmed that way. Given the opportunity to hunt the ultimate prey some people jump at that opportunity. For those in the know they would recognize my tag line.
What is more base than Alpha males killing other Alpha males?...
I’ll disagree regarding your subject persons.
As one of them, I can affirm that not one of my peers in the community ever stated that they enjoyed the work. They just know that it had to be done and that would rather they do it than their sons.
Ask a warrior about peace, they know the cost, personal and collective, about war.