Cllr Nick Paget-Brown is the Leader of Kensington and Chelsea Council.

In the last few years, some 850 British residents are thought to have gone out to Syria and Iraq to join ISIS and other jihadist organisations. Many of those were young people, and several were from Kensington and Chelsea.

Of that 850, we know that about 75 have so far been convicted by the authorities and about 70 are believed to have been killed. Although it remains to be verified, one of those killed is probably Khadiza Sultana, one of the three Bethnal Green teenagers who went to Syria – she was 17 years old.

And of course for years now we have seen young British people getting involved in terror plots, domestic and foreign.

There is nothing new, sadly, about people from ordinary backgrounds and loving homes committing to belief systems that espouse hatred and sanctify violence. In fact, people have been prey to sudden-onset fanaticism at many different times and in many different cultures.

Sophisticated, ruthless people understand this; through experiment, trial and error, they have refined their techniques for recruiting the vulnerable. Some of the material these people produce and make available through social media can be frighteningly compelling and have clearly been effective in the West.

This is the perplexing – some might say terrifying – context in which the Government’s Prevent strategy has been operating. Prevent is designed to stop people from becoming terrorists or supporting terrorism. It tries to counter terrorist ideology and challenge those who promote it. Crucially, it supports individuals who are vulnerable against becoming radicalised.

But if you think Prevent is only about Islamic extremism you are wrong. There is, for example, a growing problem with the far right, though that liberally applied term doesn’t quite capture the problem. In parts of the UK, extreme ethno-nationalism – such as that espoused by Thomas Mair, the murderer of Jo Cox MP – is now said to be generating more Prevent referrals than Islamism.

Unfortunately Prevent itself has in recent months been under attack. Now it is understandable that members of some of the families and communities from which referrals to Prevent are made are going to be concerned. But those who know and understand the programme recognise that far from being an intrusive instrument of State control, Prevent is actually just another way in which teachers, youth workers, social workers, doctors and other professionals seek to safeguard the vulnerable from harm.

The harm in question is particularly pernicious and needs a suitably sensitive, sophisticated and joined-up response and – by orchestrating the efforts of families, communities and a wide range of professionals – that is what Prevent seeks to provide. And of the referrals they receive, only about ten per cent are referred on to Channel whose job it is to provide direct support to vulnerable people at risk. That’s right, the great majority of Prevent referrals are actually rejected, though in many cases they are vulnerable in some other way and are referred elsewhere for help. And here’s the thing: there isn’t even anything compulsory about Channel. Its ministrations are entirely voluntary; not exactly the KGB is it?

And who makes referrals to Prevent in the first place? They come from those very same liberal professions and also from desperate families, and worried neighbours and friends.

Predictably, none of this has stopped advocacy and ‘human rights’ groups from attacking Prevent with the claim that it views Muslims through a “lens of security” or that it is a “broad brush policy” being applied to the entire Islamic community.

Just as predictably, these groups have found a chorus of support amongst student unions, a certain kind of academic, sections of the press, and politicians who prefer to turn away from uncomfortable realities.

I hope the wider public will treat these attacks as they deserve to be treated. In particular, I hope that worried families will not be swayed. My view is this: if you discover your son or daughter has been up all night watching internet material about Anders Breivik, or beheading videos on their mobile phone, if his or her behaviour has changed markedly, if he or she seems to have adopted a new world view that is angry and binary, if you are terrified your child might commit crimes against their fellow citizens, end up in prison or dead like poor Khadiza Sultana, then you should talk to those professionals whom in other contexts you trust implicitly, your head teacher say, your social worker if you have one, or your local children’s services department.

You could even talk to Prevent directly. Far from being a sinister arm of the state, it is simply an alliance of our some of best and finest doing all they can to safeguard our vulnerable people from extremist predators.