In Acton, in West London, there is a church which has bucked the Western European trend. Its congregation has not just grown, it has grown so many times over that it has had to move into a larger building. The number of worshippers is increasing all the time. Sadly this is not a success story but rather the result of a historic tragedy.

The Syriac church in London is largely populated by those who have fled the ethnic religious cleansing in Iraq and Syria. At least 70 per cent of the current congregation has come to Britain in the last decade, and especially in the last few years, as ISIS has been on the rise.

To speak to the congregants after Sunday service is to hear stories which seem almost impossible in the age of iPhones and the internet. Families who had lived next door to their Muslim neighbours for centuries suddenly find their neighbours turning on them, and even taking over their houses as they flee. Telephone calls from ISIS inform them that they can either convert, flee or die.

Christians have to choose what to do with elderly or disabled relatives as ISIS moves into their town. Fleeing for sanctuary in a monastery buys a few days before ISIS finds their way there too. You hear similar stories from Christians across Africa, the Middle East and Far East.

All of these people know what the Jews of the Middle East already knew and what the people of France and all Europe are presently finding out.

The murder of Father Jacques Hamel has merely brought the reality of intolerance closer to home than it has been for centuries.

What happened in Rouen on Tuesday has come after a fortnight of terrible violence and slaughter. The truck attack in Nice, the train attack in Bavaria, the suicide bombing in Ansbach, the assault on a mother and her daughters near Montpelier, the machete assault in Stuttgart: all these attacks and more have been carried out by male Muslims shouting 'Allahu Akbar' ('Allah is greatest').

The targets have been well chosen. The sea-front in Nice, like a train in Germany, could have affected anyone. If the aim of terrorism is to spread terror then targeting any random public place is an effective way to succeed in your goal.

But some of this terror is far more targeted. The attack on the offices of Charlie Hebdo in Paris last year was a specific operation by al-Qaeda in the Yemen to attempt to enforce Islamic blasphemy laws in Europe. This week's attack on Rouen is a reminder of the historic hatred expressed towards Christianity from Islam, but its target too is well chosen.

However, it points to a problem which is so big that it can barely be talked about in polite company, let alone written about.

The matter of our present self-delusion is a delicate one. Like raising Islamic antisemitism, there is a price to pay for mentioning Islamic bigotry towards Christians. Say that the religions should all get along and that more unites them than divides them and you will go far in our societies. Point out that the point of religions is that they disagree on all the fundamental issues and you tread on some of the most uncomfortable fibs of our time.

In our multi-faith, multi-cultural societies we think we should play down differences in order not to make them worse. It is a noble aim but it delivers an advantage to any religious fundamentalist who feels differently.

Consider how swiftly a few Muslims with rifles and many thousands more who silently approve have been able to shut down any criticism at all of Islam's founder. And it's not just Mohammed who is off limits.

This week as the news was coming out about the slaughter of Father Hamel, a leading figure in the Muslim Council of Britain was, among others, complaining angrily about the children's cartoon Fireman Sam. If you missed this demeaning episode (I refer to the incident, not to what I'm certain was a characteristically excellent edition of Fireman Sam) then this is what happened. A scene in the children's show had a character slipping while holding a tea tray. Papers scatter in the air. In a blink-and-you'll-miss-it moment one of the pages appeared to have writing on it. Closer inspection by the MCB representative showed it to be text in Arabic from the Quran. Cue outrage.

Indeed the outrage over the appearance of Quranic texts in Fireman Sam was so severe that for a period it almost looked like taking attention away from two Muslims going into a French church during the Eucharist and slitting the throat of the priest.

Everybody now knows, from Fireman Sam to the church in Rouen, that we all live under the threat of Islamic violence. And we know that this is not about a few extremists alone. It is about mainstream interpretations of the religion and mainstream clerics who preach hatred of 'infidels', Jews, apostates and others.

All religions have their problems. But no religion has problems like Islam. A Christian pastor preaching hate is a pariah in the faith. A Muslim leader in large parts of the world who does not preach hate is a serious outrider.

There are those who say it's just a matter of time. Christians and Jews are used to their religions being critiqued and disagreed with because they are older and Islam just has to catch up. People who make this argument forget that what we are seeing at the moment around the world may well be a fully grown-up Islam.

Polls around the world - including in the UK - continue to suggest that sizeable minorities of Muslims agree that punishment of non-Muslims for 'blasphemy' is acceptable.

A poll taken in the UK after the Charlie Hebdo attacks showed that 27 per cent of British Muslims had 'some sympathy' with the terrorists.

This hatred and intolerance applies across the Islamic world to people of other religions.

Here in Britain we like to think our 'I'd like to teach the world to sing' ethos will catch on in another couple of centuries. But Jewish leaders and others consistently embolden the extremists through 'inter-faith dialogues' where gullible or under-informed Christians and Jews are taken advantage of and used by some seriously bad people.

These 'leaders' can have no idea what they are dealing with. The persecution and slaughter of Christians in Pakistan is not a coincidence. The Muslims who gun down churchgoers across Africa do not get their ideas from nowhere. That same bigotry and hatred expressed across the Middle East is the reason why - with the exception of the State of Israel - Christianity is currently dying out in the continent that gave it birth.

As I say, many Jews know this. Many good Muslims are aware of it but are terrified of the implications.

Needless to say, an increasing number of Christians and secularists are waking up. The last fortnight has awoken more people, but it should also remind us that our communal and political leadership has more dreaming yet to do.

Douglas Murray is Associate Director of the Henry Jackson Society