So, veteran here. I’ve tried to talk people out of joining the military or at least trying to avoid jobs with high probability of seeing combat. Usually the result is they just start prying about what combat is like and make statements about how much they want to experience it.

Another tack I haven’t tried but it might be more effective, is to describe how miserable it is to have the stench of a burn pit wafting over you, always wondering if the distant gunfire will move in your direction, being stuck manning a 24/7 watch where if even one person who can do that job dies or is otherwise incapacitated you will be stuck doing 12hr shifts instead of 8. Then you get back home and have to fight tooth and nail for benefits from the country that fucked your life up in the first place.

War is hell, coming home is hell, forcing that on someone can only be justified if they are literally at home fighting off an invading force.