When the bombs went off on July 7, I was in London for, appropriately as it turned out, an Ofsted conference on history. I say appropriately because, as one of the speakers at the conference pointed out, whatever was going on out there had reasons behind it, and those reasons lie in history, and it is only with a grasp of history that we can try to understand it.

The subtext was that in such a tight curriculum there is never time to consider the origins of the modern conflict in Palestine or Iraq. Not surprisingly, this message went down well with an audience of history teachers. I think, however, that the implications for schools of the current crisis go rather deeper than just teaching about the history of the Middle East.

What we did not know on the morning of July 7 was how closely involved the British education system was with those terrible events. The attackers were British and had been through British schools; one of the bombers’ photos shown on the news was clearly a school portrait and one bomber was a respected primary school learning mentor.

Amid the appalled reaction to the bombings, some pointed out that London is merely experiencing what Israel or Baghdad know only too well. True enough, but these bombers were not living under foreign occupation or in a war zone: they were products of an education system that has agonised for years about how to promote racial harmony and to instil mutual respect between different traditions and cultures. Normally it is the older generation in immigrant communities who have trouble adapting to their new homeland, but here it was younger Muslims kicking against the very culture they had been brought up in. What has gone wrong?

During the Salman Rushdie affair in the early 1990s, many teachers were taken aback by the hard-line attitudes they encountered among their Muslim pupils. All those assemblies and tutor periods about tolerance and free speech counted for nothing as young Muslims were interviewed denouncing western freedom of speech as if it was an offence against human decency.

It is tempting to see this simply as a clash between militant Islam and western values, along the lines of President Bush’s mantra “They hate our freedom”. History suggests there is a rather deeper issue at stake.

In Elizabethan England, it was thought impossible to be both a loyal Catholic and a loyal subject. Historians nowadays think there was much more support among English Catholics for Catholic threats to Elizabeth, including the Armada, than we have tended to realise. We spend so much time in schools thinking about citizenship and national identity that we can forget that for many people there have always been strong loyalties that completely override the state.

Like English Catholics hoping for a Spanish Catholic landing in 1588, British communists and fascists fought alongside their comrades, and against each other, in the Spanish Civil War. Young British Muslims fighting alongside their “Muslim brothers” in Afghanistan or Chechnya in the early years of the 21st century fit into a long historical pattern. So do the London bombs. The gunpowder plotters and the Cambridge spies were merely playing out what they saw as the local aspect of a global conflict.

The modern conflict is about what some Muslims have long seen as a wholesale assault on their faith stemming from excessive American influence over Islam’s birthplace, Saudi Arabia. Schools have contributed to this perceived conflict, not by promoting free speech or tolerance, but by overstressing another aspect of enlightenment thinking: secularism. We like to think ours is a more tolerant approach than the French one, also derived from history, of rigidly separating church and state and forbidding the Muslim headscarf in schools, yet we give off mixed and inconsistent messages.

The law says there must be a daily act of broadly Christian worship in schools, and we tell our pupils that democracy is based on respect for law, yet this law is widely and openly flouted. Schools get nervous about staging nativity plays in case they offend other faiths, yet religions are seldom offended by each other; what offends them is lack of religion. The school that appears to find religion embarrassing is not exercising religious tolerance but a sort of even-handed distaste. It can be no great surprise if some pupils pick up the message and reject it.

We often tell pupils to think globally and act locally. In this global conflict, it looks as if the bombers did just that.

Sean Lang teaches history at Long Road sixth-form college in Cambridge