OP's comment: "I have the feeling that you're not saving lifes but rather ruining them." was not very considerate either. As a veteran myself, I found that assumption highly offensive considering I was involved in multiple missions were we provided food, shelter and security to many people around the world. OP's comment was very much a naïve one because either he did not know how much good the military provides around the world, or willingly chooses to ignore it and conveniently leave it out of conversations to support his stance.

Also, ethical myths have very real effects on societies, but they are myths nonetheless. That realization may be inconvenient to some and that's fine.