In order for you to live in you sheltered, soft, protected haven called Civilization there are those that Need to take action that in it's very nature is uncivilized.
We dropped Nukes on Japan killing EVERYONE in the area to keep from spilling American blood on Japanese soil.
We firebombed cities in Germany to hault the War Machine. Killing thousands of "innocent" germans.
You better hope we NEVER have to fight like that again, because there are too many Americans that don't have the balls to realize what you have to do to survive when you fight savages, religious Zealots or Commies. Plan on your Bloodlines to live as slaves...
There is a world of difference between dropping bombs and killing civilians as collateral damage and going up to someone, a child who is begging for his no less, and shooting them in the head. If you are capable of doing that, of deliberately and in cold blood killing a child up close, who is begging for their life, there isnt really any further for you to sink and no real lines left for you to cross. After that, raping a or beating a woman or a child would be no big deal. Maybe kill them afterwards. All whilst gazing into their terrified eyes as you do so. No biggie, right?