Terrible though the events of Black Friday were they were not so terrible that the rest of the world should simply wring its hands in despair and start making demands for revenge.

First things first: it was clearly an outrage that a young Tunisian man should gun down a host of innocent people on a beach for no other reason than they were "unbelievers". The same stricture applies to another young man who blew himself up in a Kuwait mosque to kill 25 worshippers who just happened to be from a sect that is not his own. Or to the delivery driver in France who decapitated another man in the name of jihad.

There is a common strand to all three crimes: they were committed in the name of the Islamic State, the rogue fundamentalist butchers who commemorated the arrival of Ramadan by appealing to Muslims to turn this holy time into a "month of disaster" for non-believers all over the world. Ever since IS came into being last year with its insane dreams of creating a global caliphate dominated by extreme tenets of Islam it has brought nothing but horror to the world. It has taken over vast swathes of the Middle East bringing with it a regime that is bigoted and fascistic and it operates in a fashion that is both immoral and criminal. It rapes, it enslaves, it tortures, it murders.

At the same time, perhaps because it promotes itself as being righteous and idealistic, IS has attracted to its ranks hordes of young Muslims many of whom feel disenfranchised from western culture and yearn to return to what they believe to be more basic values. The reality is somewhat different. IS has created nothing but a plague of terror and is little more than a vile parody of any true religion. Faced by that kind of nihilism all moderate Islamic clerics and religious leaders are trying to find a unified voice capable of resisting something that besmirches their own beliefs and traduces their young people.

The same holds true for the west which has not been entirely innocent in its dealings with the world of Islam as the invasion of Iraq in 2003 showed only too clearly. Confronted by the evil face of extremism with its decapitations and suicide bombs the response has been of the eye for an eye variety. So far the only reaction has been a bombing campaign which has not only failed to achieve any tangible results but may even have made things worse.

So, how does the world face up to the bloodstained philosophy of the Islamic State? It cannot be destroyed by outsiders and being realistic only a unified global response - including the muslim world - can bring it to an end even though that will take time and patience. A start could be made by trying to understand the dynamics of extreme Islam and by encouraging people of good will to combine in common cause against its worst tenets. Until then there will be more bloodstained beaches and more grieving victims.