Lets run this idea out as a thought experiment:
You are at home, going about your life as best you can, and your media shows reports of people from the other side of the globe have decided that certain members of your society are "Dangerous to their way of life", and so they have come into your country, or a country neighbouring yours, and have murdered these people. Possibly have killed that person's friends, relatives, and neighbours in the process, and attacked police/military forces along the way to get to their objectives. Maybe they've even attacked military targets directly to try and reduce the effectiveness of reprisals or just send a clear message of "Don't mess with us, or we'll kill you!"
And what exactly would be your response? Stand there and give a little golf clap, saying "Jolly good, well done on taking out my dangerous countrymen"?