History repeats - kinda

Why Did ISIS Destroy the Tomb of Jonah? | Mark Movsesian | First Things

From the post, a brief summary of the branch of Islam that ISIS represents:

ISIS is part of the Salafi movement, a branch of Sunni Islam that seeks to return to the practices of the earliest Muslims – the salaf—who lived at the time of the Prophet Mohammed and just after. The movement rejects the centuries of subsequent developments in Islam as
unjustified innovations–pagan accretions that adulterated the faith. In particular, the movement opposes the veneration of the graves of Islamic prophets and holy men. Salafis see this practice, which is associated most frequently with Sufi Islam, as a kind of idolatry, or shirk, that detracts from the absolute transcendence of God.

Salafi Islam prevails in Saudi Arabia, where it enjoys the patronage of the royal family. On the Arabian Peninsula, as now in Iraq, Salafis have destroyed the tombs of Islamic holy men. Indeed, when the Saudi royal family captured the city of Medina in the 19th century, Salafis
systematically destroyed the tombs of several of the Prophet Mohammed’s companions and family members, leaving only the Prophet’s tomb itself unmolested. There is some thought that the Saudi government plans on dismantling even that tomb, but hesitates to do so because of the uproar that would result in other Muslim communities.

In short, one should see ISIS’s destruction of the tomb of Jonah as an act principally directed at other Muslims, not Christians.

As someone says in comments following:

Can we just get this over with and acknowledge that ISIS is a 21st century version of Cromwell's army?

I initially thought that, given the images of heads on stakes in the media today, this may be being a bit harsh on Cromwell.  But I see that he was in fact ruthless, particularly in Ireland:

The first major town Cromwell and his army encountered when they landed in Ireland was Drogheda. He summoned the royalist commander and invited him to surrender. When he refused, Cromwell's model army seized the town and put the entire garrison of 2,500 officers and men to the sword. It was an act of ruthlessness which sent shockwaves of fear through the rest of Ireland. Other towns surrendered as soon as Cromwell's army approached, and their inmates were spared.

Only Wexford refused. During the siege there Parliamentarian troops broke into the town while negotiations for its surrender were ongoing, and sacked it, killing about 2,000 soldiers and 1,500 townspeople and burning much of the town.

 If one is desperate to find an optimistic take on this, I can try this:   Cromwell was operating pretty close to 1,600 years after the death of the founder of his religion.  ISIS is operating 1,400 years after the death of their's.   On this trajectory, Islam is perhaps 200 years ahead of Christianity's timetable towards becoming "mostly harmless", and everything should be looking good by 2200*.

*  Climate change will have given the world something else to fight over by then, anyway.