In London, by contrast, the images are grainy and stilted - what you'd expect from a security camera. They show three British teenagers, Muslims of migrant origin, sashaying through an airport terminal. But the image has its own horror: apparently these young things are bound for Syria, to sign on as IS brides.

Such is the daily grind of news in the Iraq-Syria conflict. But a consensus is emerging that the "state" of the self-anointed caliph, Abu Bakr al-Baghdadi, cannot sustain itself. Sure, it will continue to horrify, but it cannot last.

So what are we waiting for?

In Raqqa, the Syrian city that is the nominal capital of IS, bookshops sell pamphlets on "permissible" sexual practices with one's female slaves. Punishment, often dispensed summarily, is brutal – human heads are stuck on stakes in the central square, sometimes with a sign explaining the victim's crime.

There is a semblance of government – separate military and bureaucratic hierarchies, ministries, courts and police forces. Pre-existing education, health, telco and electrical systems have been co-opted – but water and electricity are erratic to non-existent; drugs are in short supply; and many schools are shuttered.

In a peculiar twist, some services in the IS-controlled areas of Syria are reportedly still run by Damascus. Another peculiarity: in Iraq, $US130 million ($165 million) for monthly public service pay cheques are still couriered into IS-controlled Mosul by Baghdad – and as much as half is skimmed by IS.

IS has extensive weapons stores and an estimated 30,000 fighters, with foreign volunteers pouring in. But it doesn't have the professional, technical and managerial class it needs to run whole cities and territory with a combined population of more than 6 million people.

A resident of IS-controlled Mosul, in the north of Iraq, told The Financial Times: "When I was seven years old, the war against Iran started. Since then we've been at war. We've endured international sanctions, poverty and injustice. But it was never worse than it is now."

IS Inc is a diverse, self-funding entity. It sells oil on the regional black market, even as world prices have tumbled. US air strikes have damaged many of its oil facilities, but  it  has reportedly acquired modular mini-refineries to replace them. It trades in antiquities and smuggles cigarettes and other goods; it extorts, abducts and demands ransom.

Taking extremism seriously

Middle East history is proof enough that a thug with an army can survive in the desert, bending and breaking others to his will. So perhaps the real surprise in the gory saga of IS is that we are surprised.

In grappling to explain and to understand, there are continual efforts to make Islam the problem, most notably a treatise published in the March issue of The Atlantic by Canadian journalist Graeme Wood. Most of its 10,000 words were devoted to a painstaking analysis of the IS interpretation of Islam – and ipso facto, Islam is the problem.

"The reality is that IS is Islamic, very Islamic," Wood writes. "Yes, it has attracted psychopaths and adventure seekers, drawn largely from the disaffected populations of the Middle East and Europe. But the religion preached by its most ardent followers derives from coherent and even learned interpretations of Islam."

But when an earlier iteration of IS rose up in Iraq in the aftermath of the US-led invasion in 2003, the tribes in western Anbar province - fellow Sunnis - revolted and with American help vanquished the movement that called itself al-Qaeda in Iraq (AQI). If the Iraqi tribes were willing to see off AQI, why do they acquiesce in the face of the greater horror of IS?

The answer is in Baghdad, not in the Koran. The Bush administration was able to peel dozens of Sunni tribes away from AQI leader Abu Musab al-Zarqawi in the troop surge of 2007. But writing in the March-April edition of Foreign Affairs, Professor Audrey Kurth Cronin of George Mason University warns that the logic of US counterinsurgency then does not suit the IS conflict, because "the Shiite-dominated Iraqi government has so badly undercut its own political legitimacy that it might be impossible to restore it . . . and [Washington] cannot lend legitimacy to a government it no longer controls".

The flawed logic of The Atlantic piece demands that the West and the region must take IS leader Abu Bakr al-Baghdadi seriously – as opposed to being serious about how they confront his deranged movement.

IS is utterly alone in the world. The Afghan Taliban had generous allies in Saudi Arabia, Pakistan and the UAE, but diplomatically, Baghdadi is on his own. Similarly, nothing approximating loyalty or respect informs the IS relationship with communities it controls – either it imposes itself by bloody, brute force, or it is embraced by Sunnis who see it as protection against what they perceive as the more menacing barrel-bomber Bashar al-Assad or the Iranian-backed Shiite militias that have become the spearhead in Baghdad's defence – hence the presence in the ranks of IS of so many from the security forces of Saddam Hussein.

The former Baathist military men and Sunni tribal sheikhs are essential to IS. The sheikhs deliver grassroots compliance, if not loyalty; and the Baathists offer knowledge of how to run a fighting force and an understanding of Baghdad's sprawling security apparatus.

There is a degree of pragmatism in how IS deals with Iraq's tribes. Late last year, I had it explained to me by people living under IS in Fallujah, Iraq; and Michael Weiss and Hassan Hassanlay it out in their book ISIS: Inside the Army of Terror: IS deftly manages tribal politics, offering itself as an objective arbiter in local disputes and playing off young turks against their more seasoned, cautious elders.

To focus on IS as Islamic is to allow religion to obscure what the movement's other characteristics reveal about cause and effect in the region. IS is Sunni, it has strong Baathist elements and it is tribal. All these tell us something.

A tragedy of errors

Much of The Atlantic's controversial piece turned on the views of Princeton academic Bernard Haykel, but in subsequent interviews Haykel disowns the notion that Islamic texts and theology necessitated the creation of groups like IS or that Muslims who challenge its perverted interpretations of Islam are somehow un-Muslim. "I think that [IS] is a product of very contingent, contextual, historical factors," Haykel told the ThinkProgress blog. "There's nothing predetermined in Islam that would lead to [IS].

"Sunni Muslims feel really beleaguered . . . it's very hard for Sunnis to say, today, 'let's go and fight [IS] militarily', when you also have, let's say, the Assad regime killing hundreds of thousands of Sunni Muslims, or Iran and its forces in Iraq and Syria and Lebanon attacking Sunnis at the same time.

"I see [IS] as a symptom of a much deeper structural set of problems in the Sunni Arab world. [It has] to do with politics, with education and the lack thereof, with authoritarianism, with foreign intervention, with the curse of oil . . . I think that even if [IS] were to disappear, the underlying causes that produced [IS] would not disappear."

Washington and its allies seem resigned to a belief that their choices in the region are limited to anarchy or autocracy. But the Brookings Institution's Shadi Hamid sees a way out: "If [IS] and what will surely be a growing list of imitators are to be defeated, then statehood and, more importantly, states that are inclusive and accountable to their own people, are essential."

Despite all IS' "end of days" rhetoric and its taunting of the West, the movement's savagery is more calculated than it is apocalyptic. As noted by Taliban scholar Ahmed Rashid, IS was born in ungovernable chaos; is more interested in regional territorial gains than in global jihad; it sucks in foreign fighters by the thousand, but its enemy is local and Muslim; it's militarily competent – it has good command and control, intelligence, logistics and mobility. And just as the Taliban danced on both sides of the Afghanistan-Pakistan border, so too does IS on the line that was the Iraq-Syria border.

But IS also relies on great good luck, mostly in the form of the incompetence of others – who would have thought that after the US invested $25 billion in standing up a new Iraqi national army, that that force would collapse so quickly to reveal the hollowness of the new Iraqi state? Who could have banked on Iran's investment in a new, parallel Iraqi security force – a network of Shiite militias, effectively Washington and Canberra's allies in this war - whose bloodthirsty and brutal tactics have caused many of the Sunni tribes of Iraq to opt for what they see as a lesser evil in IS?

Who could have relied on Syria's Bashar al-Assad to preside over the death of hundreds of thousands of his own people, abandoning Syria's eastern flank because he wanted to fight for the more populous, richer west of the country?

The regional powers have also stoked this orgy of violence, in a desperate bid to score points off each other. They insist that IS represents an existential threat, but they are only bit players in the fight against it – they send a few aircraft, but  none of them will send their armies to fight on the ground.

Similarly, the trillion-dollar security machine built by Washington in the wake of the 9/11 attacks leaves the US wrong-footed in confronting IS –  as a self-funding quasi-state with a near-conventional army, IS is not the same terrorist beast as al-Qaeda, so all "the counterterrorism and counterinsurgency strategies that greatly diminished the threat from al-Qaeda will not work against [IS]",  says Kurth Cronin.

Ahmed Rashid raps Western knuckles for a knee-jerk resort to military operations instead of seeking new regional alliances and prodding Muslim leaders to deal with their own problems. He writes: "The lack of leadership is most visible in the Muslim world . . . there is silence, helplessness and hopelessness . . . nowhere is civil society strong enough to demand greater action against extremism."

Mapping a new Middle East

Washington, meanwhile, is disturbingly confident that its retraining of the Iraqi Army - which it had already trained once - will forge a force capable of retaking Mosul, the northern city it abandoned so quickly last year. American plans to train supposedly "moderate" rebels to fight the forces of Assad and IS in Syria remain embryonic.

It seems that containment will likely emerge as the default response, with IS having probably reached its territorial extremities. Ramzy Mardini, a fellow at the Atlantic Council's Rafik Hariri Centre for the Middle East, says: "It's no coincidence that the militants' gains have been limited to areas populated by disenfranchised Sunnis eager for protection from Shiite forces.

"[IS] is thriving in the midst of sectarian cleavages, established insurgencies, and weak or non-existent state institutions. Hence, its support in Iraq and Syria is not the rule – it is the exception."

One of the keys is convincing the Sunni sheikhs of Iraq to break their Faustian pact with IS – and to achieve that, Washington needs to step out as what Kurth Cronin calls a "diplomatic superpower", not a military one. But winning the tribes over will in all likelihood require that they get what Washington delivered in 1991 for the similarly-sized Kurdish community in the north of Iraq – a degree of autonomy and a cut of the oil revenue that pretty well allows them to make their own way. And regionally there can be no resolution unless Iran is brought into the tent of nations – and that won't happen unless Tehran gets a nuclear deal it can live with, and Washington can in turn sell that deal to Tel Aviv and Riyadh.

We think that dealing with IS is an enormous task. But that it exists is symptomatic of a still more compelling challenge – the disintegration of the near-century-old Western construct that is today's Middle East. Sarah Chayes, author of Thieves of State: Why Corruption Threatens Global Security, writes: "Nothing feeds extremism more than the in-your-face corruption and injustice" suffered by the people of so many of Washington's closest allies in the region.

As Syria and Iraq teeter towards disintegration, others warn of an even greater unravelling. Based in Beirut, former British intelligence agent and diplomat Alastair Crooke depicts IS as "a veritable time bomb inserted into the heart of the Middle East". "[IS'] real potential for destruction," he warns, "lies . . . in the implosion of Saudi Arabia as a foundation stone of the modern Middle East."