Some 400 Brits have been to Syria to fight, an estimated 20 have been killed – yet the draw is growing stronger. Last year, the number of arrests relating to Brits joining the jihadi-dominated Syrian was one a fortnight. So far this year, it’s been one every two days. The police’s appeal yesterday for Muslim women to inform on their men who are considering signing up was a sign of desperation – but they’re not sure what else to do. This is the era of cyber-jihad where social media is a massive recruiting sergeant for jihadis, and I look at this in my Telegraph column today.

The idea of indoctrinating young people so they go to fight in a foreign war is not new. It happened during the Spanish civil war – as depicted in The Prime of Miss Jean Brodie. She moulded her girls in her image, and sent one to fight for Franco in Spain – she died (clip from the film above). In the book, one of the girls is asked what happened: was it religion? Calvanism? Politics? No, came the reply, it was ‘a Miss Jean Brodie in her prime.’

A charismatic, strong leader can bend even the more intelligent minds – if they can find an audience. Once, this happened in certain mosques. Now, today’s Islamist equivalents of Miss Jean Brodie are everywhere. A brilliant study by Shiraz Maher, one of our bloggers, and his colleagues at King’s College London documents the extent to which social media is helping to recruit some 11,000 foreign fighters in Syria and an estimated 3,000 of them are Western. These guys are given to keeping their Facebook and Twitter followers posted. The King College’s analysis shows there are two main Islamists that they follow.

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But another major factor is peer-to-peer indoctrination. YouTube is currently hosting a few videos from British jihadis, inviting people to come and join them. Look at the below: a Brit showing people around his home in Syria and inviting more to join them.