Isil cannot be defeated by war so we must shut down its hate speech on internet
It can happen anywhere, it can happen to anyone - that was the subtext to an odious attack in Normandy this week, in which an elderly priest was butchered at the altar as he celebrated Mass. The teenage fanatics who filmed themselves slaughtering him in the name of Allah have ratcheted up the chill factor in a war that is difficult to comprehend, let alone combat.
Father Jacques Hamel's murder is the latest in a succession of terror strikes, all posing security and political dilemmas for other Western states which are also vulnerable to attack by disaffected young men with a death wish.
With whom can we negotiate to bring an end to the violence? How do we stop young men from being sucked into jihad? How to block the false message that acts of brutality will turn them into martyrs for a just cause?
We have experience of terrorism in this country, but not terrorism of this nature. The aims of those engaging in violence in Ireland could be addressed by equality of opportunity, including jobs, education and housing.
Also, IRA volunteers had no ambitions to reach paradise quickly, in marked contrast to jihadists. Negotiation was therefore possible.
However, Isil seeks to overthrow the Christian world and no common ground for bargaining is feasible on that basis. In addition, it has harnessed the internet as a worldwide recruiting sergeant.
This allows Isil to enrol and organise Islamic Schwarzeneggers from around the world - the godfathers need never leave their bunkers thousands of miles away.
They simply programme their sheep and send them out to kill and be killed. Somebody only has to take life two or three times before they lose their inhibitions - it's called 'acquired psychopathy'.
Now some French media outlets have decided on a photo blackout of jihadists to avoid advancing their posthumous martyrdom. There are concerns about news reports acting as a recruitment drive for terrorists, with Western media used to exalt their campaign. Coverage of atrocities is cherry-picked for propaganda purposes: look how frightened we've made them. See how our brother is a hero.
One of Fr Hamel's murderers was Adel Kermiche, who twice attempted to join Isil in Syria. Before turning militant, he was a sports-mad kid who liked 'The Simpsons' and Rihanna.
Friends tell how he quoted verses from the Koran when they tried to argue with him.
"He was bewitched," his mother said afterwards. Predictably, he and his fellow conspirator, both just 19, ended up dead themselves - shot by French police. They are victims, these new recruits - 21st-century cannon fodder.
France has suffered 11 terror attacks or attempts since gunmen stormed the Paris office of the Charlie Hebdo magazine 18 months ago. More than 240 people have lost their lives. Attacks have also happened in Germany.
Consequently, fear is spreading of sleeper cells in other countries, waiting to spring into life like bogeymen hiding under the bed.
What do these young men share in common, other than a willingness to massacre others?
Their attention is captured in the first instance because they are alienated, feeling their lives have no meaning. This radical version of Islamist ideology persuades them that killing is God's will and they will be bathed in glory for doing it. Suddenly, their lives have meaning.
Much of the bile is churned out via social media - a world of online extremism is readily accessible. Social media provides an introduction to fanaticism.
From covert Twitter or Facebook, it can be a short step to chat room forums, where hate indoctrination is discharged by militants. Al-Qa'ida has used Twitter, while instructions for bomb-making can be accessed on the internet, although social media is doing everything it can to prevent its exploitation by terrorists.
Converts to radical Islam tend to be male and aged between 18 and 30. They are drawn from a variety of socio-economic and family circumstances - lack of opportunity is not always the trigger. It is too simplistic to suggest they are brutalised by poor prospects or because they are marginalised.
There are countless people worldwide with little by way of education or prospects who do not become jihadists.
But we do know that recruits feel a sense of self-esteem after being radicalised by mentors who convince them that their cause is sanctioned by Allah.
That sense of self-worth appears to be a key factor. Sadly, there is nothing done in the name of Isil that isn't endorsed either in the Koran or the traditions (the Hadith). These people know their scriptures - or at least how to find corroboration for their actions within them. Extremists selectively take passages from the Koran and ignore other sections which don't suit their purposes.
It is problematic that Islam is not fundamentally a religion of peace, despite its leaders frequently insisting the opposite.
Christianity has been violent, too - the Crusades were authorised in the first place by Pope Urban II. But they happened between the 11th and 15th centuries and Christianity has since reclaimed its original ground as a peaceful religion. Meanwhile, Islam has had no Reformation or Enlightenment, unlike the Christian world, and it is too easy for some branches of Islam - not all practitioners, of course - to slam into reverse.
Islam itself needs to seek ways to deal with this dilemma. While many clerics urge peace, some promote a holy war. Their zealous interpretation of Islam is feeding off gullible young men.
One of the 2013 Boston Marathon bombers, Tamerlan Tsarnaev, had a social media presence bristling with clips of extremist clerics, for example.
His brother and co-bomber Dzhokhar told investigators that he and Tamerlan struck because they wanted to defend Islam.
A cohort of confused young men has always existed and probably always will. Unfortunately, Isil points a glamorous path to martyrdom - permission to swagger about with weapons, strike a blow for Islam and die an apparently glorious death. Such an ideology cannot be beaten by warfare. The contest now is to find ways to shut down the lies and block the duplicitous message.
Silencing the radical clerics and stopping the recruiting sergeants are important steps, while the peaceful followers of Islam can - and I believe are willing to - help deal with this challenge.