Interesting question... short answer is that I have absolutely no idea. Crusades used to be a thing, I would imagine this is a very good reason for one...
I would guess that our increased sharing of information has allowed us to vent our frustrations through media which has become somewhat of an anger management tool to help dissuade fundamental viewpoints from taking hold. I'm not sure but I doubt there are many Christians in the area the conflict is occurring so a direct, back against the wall response is unlikely to develop as easily. I imagine Israel will be brought into this in the not too distant future when IS set their sites on their holy land; then the world is in for some horrifying moments of witnessing history. Perhaps most Christian nations are content with how America handles things so they are happy to kick up a fuss with rhetoric and help encourage America to act. Other than that I am not sure, perhaps there aren't enough Christian extremists to unlock the outrage of what is happening.