We were all once barbaric (in many, many ways, still are). How did we get out of it? Education, not by some enlightened assholes blowing us up. Please take a step back from your emotion and think about what you're saying.
Again, we didn't start this fight and we cannot coexist. This is not a matter of live and let live, as they won't let us live. The fundamentalists are expansionist, and are not happy unless everyone believes as they do. Take this attack, for instance. In Islam, you are forbidden from insulting the Prophet. Fine. If you're Muslim, then don't insult the Prophet.
That's not enough for them. They want everyone else to follow their dictates, too. Where they are not followed, these people think it entirely reasonable to murder innocents unconnected to the original "offense". Our only options, here, are to either respond with force or acquiesce. If we choose the latter, we have abandoned our values of free speech in favour of their values of adherence to their dogma. This cannot be.