I've had the chance to talk with people that have worked at/done internships with MIC contractors and DOD labs etc. Here's one of the responses I've gotten (asking what they think about the civilian casualties their weapons have caused, because they kept insisting that these were moral grey areas)

No, I dont think is bad. There is really good people in the uniformed services. They just do a job not everyone cant handle... they go to psychologist for a reason.

Murder of civilians is a complex topic... and a really sad one. Sometimes civilians attack soldiers on duty in some countries and sometimes they are involved in the damage done without reason (this is bad for me).

In a peaceful world where humans did not have the need for warfare... (following your line of thought) I would think it is unnecessary.