I wasn't in the military, but many of my family was and my wife's family were.
I know when talking about things, they tend to well up with tears and might stare or actually re-live some of those moments when they were trained machines made to kill and destroy. After they become human like again, they all have different ways of dealing with something that is basically against their core value.
In my opinion, there's never anything wrong with defending your home or land, but when you're sent to do a job such as this.... your patriotic duty calls you and you want to do your best.
I don't think there's anything specifically wrong with Arlo's question about the enemy, but I can see how it could affect some. A friend of mine.... his son was a point-man with his own ammo carrier person. He went through quite a few tours and would never brag or talk about this stuff. He elaborated on his guns, their weight, how much ammo he carried, but never what he thought or did while in action. One day.... after he got out..... he just started talking about what he did and did the chit hit the fan then. He told us what it was like, the enemy, how many he knew he took out, let alone how many he was thought to have taken out. He talked about blowing up military transports and buildings. He was the first guy in and saw lotsa action. Between him and his ammo carrier... he had just about every weapon you could imagine. I always imagines Rambo, except little Kenny had little muscles and wasn't on steroids. Anyway, he never again, that I know of, ever spoke about it again. Last I saw him, he was having a rough time fitting back into civilian life.
My neighbor was in the Nave during WWII and was on a tanker. He ran fuel and supplies all over the South Pacific. He was on the ship right next to where the Japanese surrendered. He witnessed the whole thing. He talks all the time about the war, but he never really saw any real fighting. They were shot at and made some quick getaways, but hardly ever fired their cannons at the enemy. They were well protected.
Guess it depends on who you ask...........