@Shademp
There was an article in Scientific American in 2010 about soldiers who enjoy killing, if you are interested in checking it out.
https://blogs.scientificamerican.com/cross-check/why-soldiers-get-a-kick-out-of-killing/
I don't think it is at all surprising that sadists and psychopaths gravitate to careers that allow them to kill and torture with relative impunity. Some of them might mask it behind a facade of jingoism, but most of the time it is, as with most human behaviors, all about power. True fanatics can be ruthless, but a display of gleeful bloodlust indicates that a person's violence is driven by more than a sense of duty. The sadistic soldier shows up in many (non-propagandistic) war movies (the
"Get some!" guy from Full Metal Jacket comes to mind). He is usually throwing around racial slurs and other dehumanizing language and openly can't wait to rape and pillage. TVTropes even has
a page for it and describes it as "truth in television."
Killing and torturing are the consummate acts of power because they involve complete subjugation of another person's entire existence to one's own. Erich Fromm wrote, "The pleasure in complete domination over another person (or other animate creature) is the very essence of the sadistic drive. Another way of formulating the same thought is to say that the aim of sadism is to transform man into a thing, something animate into something inanimate, since by complete and absolute control the living loses one essential quality of life - freedom." Most people, thankfully, don't want that power and are sickened by experiencing it. But a smaller number of people crave it and thrive on it.
I think everybody has an inner sadist, to a greater or lesser extent. We all get off on flexing and lording things over others. That's just part of having an ego. So it's not that the sadistic instinct is *alien*, but it becomes rampant and out of control in certain individuals, usually due to certain types of childhood experiences coupled with neurological and genetic predispositions. You will find these people among the ranks of *any* position that enables them to exert power over others - politics, banking, middle management, teaching, prison staff, the military, et cetera.
A study was conducted where people who had just experienced rejection were given the chance to make another person drink some amount of hot sauce. They were told that the subject didn't like spicy things. Surprise-surprise, the people who were still smarting from a wounded ego were wayyyy meaner with the hot sauce than the control group. And the people who were identified as having high rejection sensitivity were the meanest of all. When you feel small, you can feel bigger by making someone else feel small. And killing another person - holding their entire being your hand like a glass ball and then dropping it from a height and going "whoopsie" - is at the far end of that continuum.
This article has some fascinating insights as well:
https://www.bbc.com/future/article/20150130-the-man-who-studies-evil
I'm definitely not a psychologist, but sadism is something that I explore quite a bit in my writing, so I thought I would weigh in.