Such a strategy will achieve at best a truncated caliphate--roughly ISIS's current territory--surrounded by hostile Sunni and Shia states, which will soon be the scene of further conflict as the ex-Baathists struggle for control. Their tactical alliance with ISIS can't last. At that point, ISIS will be forced to look to their Saudi foes for support, but this again is not a stable alliance, as the Saudi betrayal of the Ikhwan in the 1920s reminds us.
This caliphate revival, the goal of Bin Laden, of HuT, and stretching back to the Ikhwan in the 1920s and Afghani in the nineteenth century, should have ended with the US invasions following 9/11, which aimed at destroying al-Qaeda and consolidating US hegemony in the region. However, the US invasions of Afghanistan and Iraq proved to be a boon to these "neo-Wahhabis", and all Obama's horse and all of his men now look quite helpless.
By backing the Syrian insurgency, the US gave at least free rein (if not actual support) to ISIS, who presumably were only supposed to be spoilers, weaken Assad, possibly split up Syria and Iraq, but certainly not to gain power and keep it. With that now a possibility, the US is panicking, as well it should. So far, the Saudis aren't panicking, presumably counting on using their oil wealth and anti-Shia sectarianism to let them co-opt leaders of some future Sunni Iraqi-Syrian state.
Perhaps they count on the US to drone ISIS out of existence and replace them with pro-US Sunnis. But this no longer looks like an option either. ISIS types are prepared to die in their jihad, like the Ikhwan insurgents a century ago, and it is unlikely that ISIS will be seduced by either the empire or a bankrupt monarchy.
Acceding to a rump caliphate would be the equivalent of the British making peace in the 1920s with the Ikhwan, an impossibility in terms of empire strategy. Now, as then, Saudi hegemony must be preserved. Now, as then, Saudi collapse would mean an end to imperial control over the vital region.
A new regional alignment
ISIS's sectarian success is prompting calls for a nonsectarian alliance between governments in Syria, Iraq, Iran and possibly Turkey opposed to this scenario. Turkish support for the insurgency in Syria is already being seen as a mistake, encouraging Kurdish separatism, and Turkey's Islamists have no truck with ISIS. A proposal by Diako Hosseini of the Iranian Ministry of Foreign Affairs Institute for Political and International Studies is the establishment of a rapid deployment force by the neighboring countries of Iraq, centered on Iran and Turkey, which would act on the request of the Iraqi government.
What role can the US play here? Not much, as its support is the kiss of death to Iraqis seeking to extricate themselves from a decade of US occupation, and the return of its forces would be a blow to the regional powers, who should be the actors responsible for solving the region's problems.
Such a regional alliance would stabilize the US-installed regimes in Iraq and Afghanistan, though no longer under US hegemony. The rapprochement between Sunni and Shia that it implies would bring Muslims together in a way that ISIS and its sectarian caliphate cannot do. Neither the Saudi Wahhabis nor the ISIS neo-Wahhabis are capable of making this 'leap of faith'.
A shorter version of this appeared at Middle East Eye