Gerard Russell is a Senior Research Associate at the Foreign Policy Centre and a Senior Fellow with the New America Foundation. He is the author to “Heirs of Forgotten Kingdoms”.

The “Islamic State”, or ISIS, has attracted recruits from all over the world to its particularly brutal brand of fanaticism. In the secular West, commentators seem to prefer to explain these recruits’ motivations in terms of socio-economic conditions, rather than of theology or religious passion. Yet recently a star player from democratic Tunisia’s youth football team chose to go and die in Syria. He was not marginalized or particularly poor – and neither were other Tunisians who have joined ISIL in startlingly high numbers.

The explanation for ISIS’s appeal lies elsewhere. “If a man were permitted to make all the ballads,” as Andrew Fletcher wrote, “he need not care who should make the laws of a nation.” ISIS has exploited a ballad, long in the making, which depicts Islam as the rightly dominant religion of the world, dethroned from its empire by the guiles of the West. It couples this with an interpretation that this empire was established, by the very first Muslims, through force and the ruthless suppression of all forms of heterodoxy.

Real history tells things rather differently, as I found out when researching my book about the remarkable religions which survived fourteen centuries of Islamic rule. That process began nearly ten years ago, when the high priest of the Mandaeans met me in Baghdad, and told me that his community practised the oldest religion in the world. I could believe it: the Middle East has a history that goes dizzyingly far back in time. The oldest surviving poem in the world, the Epic of Gilgamesh, was composed in Iraq over four millennia ago. What amazed me was that any of that ancient history could still be intact.

But as I discovered, there are many communities scattered about the Middle East who had lived in the world of Islam while practising their own distinctive faiths. The largest of these communities are the region’s many different Christian churches, which alone probably have around eight million members. But there are also others: Yazidis who revere the Peacock Angel and refuse to eat lettuce; mountain-dwelling Kakais; Mandaeans whose strict ritual purity is fortified by occasional immersions in the river Tigris; Zoroastrians who follow the three thousand year old Avesta of Zarathustra, and Samaritans who, isolated from all the changes that have affected their cousins, the Jews, in the past two thousand years, still practise their annual Passover sacrifice on the same mountain where Jesus encountered them two thousand years ago.

And there are branches of Islam – but utterly distant from the orthodox mainstream: Druze, who revere the Greek philosophers and believe in reincarnation and a World-Soul; and Alawites, who hold the sun and moon as sacred and practice a ritual of sacred wine-drinking. We know that these traditions were popular in the Middle East before Islam.

The survival of these ancient communities and customs tells us something with a very modern relevance. How did they survive for so many centuries in a region which appears to be permanently mired in sectarianism and religious violence? How come, in fact, they seem to have survived rather better than the equivalent, pre-Christian, religions did in Europe? And – as the Middle East’s religious violence grows worse than ever, and spreads beyond its boundaries to recruit volunteers from Europe – can we learn any solutions from that history, to solve present-day problems?

What I found, when researching my book, was that these recondite communities survived for three reasons. Mountains and marshes protected them from persecution. Governments were weaker than their equivalents in Europe, and less able to organize armies to force conversions, or clerics to ensure orthodoxy. But a third, important, reason was that there was a streak of tolerance in Islam which meant that Muslims rarely attempted to impose Islam by force. They did, sometimes – when the marshes and mountains came in handy – but there were also examples of the Middle East being far more accommodating to minorities.

A Jewish astrologer, for example, helped to found Baghdad. (The Jewish community in the city lasted until recently: when visiting Baghdad in 2003 I saw Hebrew schoolbooks, printed there in the 1950s, gathering dust in an abandoned synagogue.) A pagan mathematician was invited to work in Baghdad for the Muslim ruler, the caliph, in the ninth century when Baghdad was the greatest city in the world. Christians served the Muslim caliphs as their ministers from the very early days of the caliphate. And in the modern era, between 1860 and 1920, Egypt had three Christian prime ministers – which put Egypt back then in a better place than most European countries, in its treatment of its religious minorities.

In parallel with this, the minorities’ story tells us of the ties that bind humanity together, across racial and religious boundaries. The handshake, for example, was made popular in Europe by the cult of Mithras – an import to ancient Rome from the Middle East, where the Yazidis still practise it in its original, ritual form. Greek philosophy, with its emphasis on the sun as a metaphor for the divine spirit from which the universe emanates, helps explain why the dying words of Turner, the painter (and follower of Greek philosophy) – “The Sun is God” – would not seem strange to Syria’s Alawites, who believe something very similar themselves.

ISIS does not want those stories to be told. It claims to be recreating the caliphate through bloodshed and persecution, not learning and tolerance. And it wants to present an absolute divide between Muslims and people such as the Yazidis. But the stories are important. For although the US-led military campaign against ISIS has usefully punctured the movement’s terrifying reputation and stopped its expansion, the fight against Islamic radicalism is fundamentally about narrative, not bombs. It is about the intellectual diet that young devout Muslims are given.

That diet can be one of collective grievance, regressive and narrow-minded interpretations of religion, and selective treatment of history that excludes other faiths – a view of Islam that is presented by extremists, and unfortunately reinforced by critics of Islam who like to present it as naturally intolerant and violent. Or the narrative can be a celebration of the diversity and tolerance that has marked Islam in its finest eras. Although individuals are joining its ranks, polls show that the principal response evoked by ISIL in the Arab world is revulsion. That makes this a particularly good moment to change the ballads.