Europe seems set to make the same mistake America did after 9/11 - "They killed our people; well, they're dead, but let's go and kill a lot of other people."

Paul Burke is right. But I think he's also wrong, in that there's a kind of intoxication of brutality taking hold, when people kill hostages and circulate videos.

They don't realise - and we don't realise - that the means aren't justified by the end; the means change the end. If you use brutality in your efforts to realise your ideal society - whether that's by stoning adulterers and burning pilots to death, or by drone-bombing death-planners and assassinating your enemies - then you will end up with your ideal society tainted by the blood on your hands and the brutality that you have made the norm.