Last I checked the official stance was that any able-bodied adult or adolescent male in a war zone is considered an enemy combatant in official statistics.
Yeah, take that. What you don't talk about is that what we call ISIS today was US best friend just months ago. They were called euphemistically "moderate rebels fighting for democracy in Syria" and they were supported economically and with weapons by the US and Saudi Arabia to kill innocent people there(and put a puppet state in place).
Of course they took the weapons and crossed the border to occupy Iraq, as the failed state the US created made it so easier than fighting against a well organized, and Russia supported army.
Media creates your perceptions based on their own interest. If the news come from far away, media has total control of shaping your emotions, as you don't have family, friends, eyes or ears in the place.
But take any of the recent genocides (Rwanda) or even ISIS - innocent people are unquestionably being killed. A soldier hears about this in the news, prepares every day to stop large forces like that, and instead is being asked to stand down. The media obviously plays a large role in shaping the perspective of horrors being done in the world, and I wouldn't argue war is the solution to all but a few problems. However, it is fairly straightforward and morally defensible that innocent people would be alive if other people were killed, and soldiers are prepared and ready to kill.