King Abdullah of Jordan warned a few years ago that Iranian influence was extending in a ‘Shia Crescent’ through Shia-run Iraq and apparently honorary-Shia Syria to the Hizballah mini-state in Lebanon.

Now his Shia crescent problem has been solved by Daesh, that movement which calls itself the Islamic State (IS), which has blasted a great Sunni (Salafi, Taqfiri) wedge between the Shia South and East of Iraq and the ‘Alawi coast of Syria.

I don’t imagine King Abdullah is especially satisfied with this outcome.

Iraq has slid from shaky stability into the three-state division expected by almost everyone before the 2003 war. Syria has, thanks in part to Western and Gulf intervention, fallen into a violent fragmented limbo. Hizballah has become overextended in Syria, weakening it in Lebanon.

The lands controlled today by Daesh aren’t exactly the sort of ungoverned space we sought to prevent developing in Afghanistan, but they’re the next worst thing. The IS offers, in the short term, an opportunity for those enemies of the World’s civilised people who are Sunni Muslims to gather, plan and create nightmarish events. That is, however, a short-term problem.

Is there a military option for destroying the Islamic State? One comes to mind: unleashing Iran.

Daesh might be able to sustain itself as a coalition of tribes in the hinterlands of eastern Syria and central Iraq for a few years, but it hasn’t got legs. It won’t last as a state never mind as the apocalyptic Caliphate it dreams of being. While they have a load of cash and while they control a lot of territory, they are weak on the ability to govern well. As long as they provide a simultaneous dictionary definition for ‘rogue state’ and ‘failed state’ they won’t succeed as the Caliphate they aspire to be, or even the kind of state they despise.

As the more fanatical insurgents in Libya shop for black flags to celebrate their absorption into the Caliphate, sanctifying the event with the blood of Egyptian Copts, the question is, how should we address this new little horror?

There is a narrative that the US has been largely inactive in the face of Daesh. Recently, when I challenged someone online to tell me what the US should do, she replied that President Obama (for she blamed him for America’s alleged inaction) should build a regional coalition, arm the Kurds and attack Islamic State targets from the air. Since the US has already succeeded in doing all of these, all that remained was some unspecified exercise of military force.

Is there a military option for destroying the Islamic State?

One comes to mind: unleashing Iran. With two armed forces (the regular army and the Islamic Revolutionary Guard Corps), a firm base in southern Iraq and another on the Mediterranean coast, Iran could (at the cost of creating a regional superpower) operate with Western forces to re-incorporate Daesh-held territory into Iraq and Syria. Apart from giving the Iranians the power and stature in the region they feel they deserve, the costs would be: cementing Bashar Assad’s regime or a similar successor in power; and confirming Hizballah as the de facto governing power over much of Lebanon.

Those who think that large-scale military action is the best way to deal with Daesh must realise that only Iran has the capabilities to do the dirty work realistically.

It would not be the first time Iran helped the West deal with extremist Sunni Muslims. In the 1970s Iran rendered massive assistance to a British-led operation which protected the then-newly installed Sultan of Oman from Egyptian-supported Yemen-based insurgents. Of course at the time Iran was a monarchy close to the US and Israel. Iran was viewed as a regional counterweight to Soviet-sponsored Arab nationalism.

Theocratic Iran, uncomfortably cozy with Moscow and a bogeyman to Israel, Egypt and the Gulf kingdoms, is not nearly as welcome a helper today.

Iran is probably wise enough not to go for something like that. As a major regional player Russia is happy to support them as a counterweight to America in the region. As a regional superpower Iran would be capable of creating stable energy infrastructure in the region and that is something Russia does not wish anyone else to do. For Iran to overachieve, and to overachieve too soon, would alienate Russia; and the Iranians are too canny for that.

I don’t mention Iran facetiously. Those who think that large-scale military action is the best way to deal with Daesh must realise that only Iran has the capabilities to do the dirty work realistically. The Kurds are willing, but too few in number and too inexperienced. The Turks would not do anything to benefit the Kurds.

American, Allied and regional operations against Daesh have so far been air, logistics and special forces operations. These have enabled some successes of the Peshmerga against the Daesh forces. They offer the possibility of incremental success against the IS, preventing its expansion in the short term.

For an American-led coalition to destroy the IS and occupy eastern Syria and much of Iraq would require a very, very big force package including a sizeable land component. It would need to build up over months, and it would need to make extensive use of seaports in the region. Realistically the force would need to use a major Turkish, Syrian or Iraqi port, preferably all of the above. Aqaba could help but could not fully sustain this scale of operation. The political effect of staging through Israeli ports would be counterproductive.

An American-led joint operation with a land component would fulfil Daesh’s apocalyptic vision, based in a literal interpretation of ancient Muslim scripture, of an invasion of unbelievers to oppose the caliphate. While it is not my business to deny Daesh the fulfilment of their fondest dreams of Armageddon, neither do I think it is to the advantage of the West to provide bit players for the bloody enactment of the battle of Dabiq.

The presence of a large and potentially vulnerable land component would also provide something that Iran dearly loves: a punching bag. The Great Satan, so difficult to strike from overseas, obligingly stretches itself into the region where it can be pummelled. It did so in Iraq, and Iran would not mind much if it did so again.

So put a grand American invasion from your mind, alongside that bizarre vision of a vigorous Iranian response. This is not a problem which will be solved by a massive military campaign.

Patrick Cockburn’s latest screed tells us, I understand, that the IS will endure, which in my assessment shows that he is, in his dotage, seeing Daesh as a replay of a phenomenon he’s seen before. I haven’t read his book yet, but based on what I’ve read of it I think he’s wrong.

The hardest thing for us to do will be to back down from our well-meant but ill-judged insistence that Bashar al-Assad and his infamous crew must be done down immediately.

The Islamic State will collapse under the weight of its own ambition. It will not likely collapse soon, which is a slap in the face of every European and American foreign ministry which showed unseemly eagerness to change regimes during that promising but fruitless Arab Spring. It will not, however, remain in its current virulent form.

Like a virus which evolves in order to survive, and in doing so becomes less dangerous, Daesh will evolve. It must either become the Orthodox Muslim Caliphate it pretends to be, and in doing so discover its military weaknesses; or lose its religious legitimacy.

Ayatollah Ruholla Khomeini created the religious space for Twelver Shia Islam to become a ruling modern theocratic entity by creating in himself and his successor the High Priest with the religious and political authority to adapt his religion and culture to the requirements of a modern state.

The Caliph abu-Bakr al-Baghdadi has not taken this authority upon himself, and arguably his literalist approach to Islam does not permit him to do so. Unless he can take a step away from that literalism, by invoking a Sunni version of Khomeini’s ruling principle, he will go to his grave, sooner or later, without achieving his aims.

As realistic people we must accept barbarous governments around the world, while as ethical people we must for their eventual end. The states which adjoin the IS in the Middle East, and now potentially in North Africa, must find ways to stop this mock-Caliph from spreading his control in the short term. The rest of the world must continue to assist Jordan as it hosts a significant population of Syrian citizens and arranges their eventual repatriation.

The hardest thing for us to do will be to back down from our well-meant but ill-judged insistence that Bashar al-Assad and his infamous crew must be done down immediately. I have, ever since the Syrian insurgency began, written that one day Assad must swing, but that until the Syrian people are competent to overthrow him and replace him he must be permitted to continue his barbarous dictatorship. It will not be easy for us in the West to step back from our principled but unrealistic aim of having Assad overthrown by the summer of 2012.

The most effective action against the IS so far has come from Saudi Arabia. The Saudis traditionally consider a hundred bucks a barrel the price at which they lose money to energy efficiency and, lately, to oil shale and fracking. They are currently pumping oil at a furious rate, depressing the price of crude well below this price. This not only makes business sense for the Princes of Petroleum, it makes the IS’s greatest potential resource underperform. The low price of crude has hurt Russia, it has hurt Iran, and every barrel of black gold they sell hurts the Caliphate.

Not all of us have this option available to us. The best prescription for the rest of us is to act with an eye on the Middle East we want to see in 2020, because that is where’s today’s actions will take us. Whatever our short term intent, our actions today will shape the Turkey, the Iran and the Gulf States we get in five years’ time.