In the late 1990s, about a decade after terrorism first bespattered the Kashmir valley, champions of secularism in India would point out that Muslims from the rest of the country had never felt the need to join cause with the violence being perpetrated in the name of Islam in the northern state. Though the call for a holy war had drawn young Muslim men from Pakistan, Afghanistan and even Central Asia, not one of the Indian security forces that operated in Kashmir had captured a Muslim terrorist from West Bengal, say, or Bihar. This to many was sure-fire indication that the Indian polity was healthy and secular – a sign of the successful assimilation of a previously troubled minority.

Yet even then the argument seemed conceptually weak. The call to holy war in Kashmir could be ignored because the Bhojpuri or Malayali Muslim was as much of an outsider to Kashmir as a Hindu from Bhopal. The non-participation of Muslims in the violence in Kashmir was perhaps better read as an indication of the distance of that struggle from their daily lives – there was no emotive plank in the Kashmiri’s appeal to holy war. A generalised call to protect your religion or to fight with your religious cohorts is not sufficient to draw a peaceful person to violence. It needs sharper focus. And not just for Muslims: this is the reason LK Advani was ignored in the early 1980s but became a tidal political force later in the decade, radicalising hundreds of thousands across India when he fixed upon the Ram Janmabhoomi issue.

The first instance of Indian Muslim terror – in the definition that we have come to know it, causing wanton civilian death, targeting symbols of the state – were the 1993 bombings orchestrated by the Mumbai mobster Dawood Ibrahim, which he said was a response to the Hindutva attack on the Babri masjid. There is no doubt that the destruction of that mosque devastated the Indian Muslim community, who had suffered through numerous riots, and caused their own. But until then they had felt the state would protect places of worship important to the community. The numerous terrorist acts that have followed indicate the alienation many young Indian Muslims feel.

Yet it is more pertinent today to address the insidious radicalisation of Indian Muslims taking place from within. All over the nation, Muslims are preaching and being taught ever more codified versions of Islam. It is important to disassociate this radicalisation with terrorism – beards and burqas are a fair barometer of violence only in the imagination of some Western media. But it is also important to see these acts of terrorism as the sharp tip of a broader push within the community towards radicalised Islam. The surge in popularity of a Saudi-promoted brand of orthodox Wahabbism – a branch that has a venerable history in India, growing as a reaction to the saint veneration and shrine visitation that Islam in South Asia borrowed from Hinduism – has not been adequately documented.

Muslims in both Pakistan and India are turning away from the less doctrinaire interpretations of Islam that once typified the religion on the subcontinent. While everyone should of course be free to choose their own degree or investment in faith, it is also essential to note that fundamentalists of every religion teach fear and disapproval of the outgroup, and are thus harmful to democratic society and convivial living.

This push has been visible for more than a decade now, perhaps more for closer observers. And it could well be a response to the popular projection, within Muslim communities, of a Western war against Islamic beliefs. But even anti-Americanism among Muslims does not answer one question: why is it that fewer Indian Muslims were drawn to the jihad call of Al-Qaeda, the Taliban and Kashmir, than it seems are already being pulled towards ISIS?

A photograph has been doing the rounds of the Internet of a large group of young Tamil Muslims clad in black ISIS t-shirts. On the Internet it is being brandished by Hindu nationalists as justification for their narrow parochialism, but it should worry every citizen of India. Tamils have nothing to do with Iraq or Syria. Then why this adherence to ISIS over Al-Qaeda, indeed over the jihad in Kashmir?

The answer lies in ISIS’ rallying call. The politically savvy and militarily capable self-named Caliph of the Islamic State of Iraq and Levant, Abu Bakr al-Baghdadi, has astutely positioned his struggle as one against not the West but against Shia overreach. While many have characterised his ideology as pan-Islamist, it is in fact pan-Sunni. He seeks to create a Sunni state stretching across West Asia and the subcontinent. Needless to say, Shias will have at best subsidiary part in it.

The violence against Shias that has destroyed any claims Pakistan had left to secularism is an expression of an age-old animosity that goes to the very heart of the Islamic faith. It has been a source of conflict in every Muslim country. It is also the fault-line of the current battle in Iraq.

Sunnis are about 85% of India’s Muslim population. The ISIS t-shirts being worn by those young men in Tamil Nadu are not a reaction to Hindutva fundamentalism or Western political aggressions. They are a means of asserting Sunni pride. The photograph does not suggest to me that these men will join the jihad in West Asia. But it does suggest to me that the Sunni-Shia divide will continue to excite violence long after Western nations have ceased to be a perceived enemy of Muslims.