Return of the Khilafat

As ISIS are on the march, almost everyone is claiming it is a strategic disaster for Iraq in particular and the West in general.  No-one thinks about Iran.  Iraq under exclusive Shia-dominated government is an Iranian client state and for it to fall to Sunni jihadists would represent a significant strategic reverse for Iran after a supposed Achaememnid re-awakening of aggrandisement through Babylonia to Assad's Syria and Hezbollah in Lebanon.  It would be bad for Bashar al-Assad as land supplies through Iraq would dry up and overflights dangerous.
A caliphate or khilafat has not been in existence for almost a century, when Ataturk abolished it to create his modern Turkey.  There is little appetite for it to return, except amongst irresponsible oil-rich businessmen in the Persian Gulf who fund these jihadists.  A sense of western betrayal goes back to when the British government assured Muslims in the Indian Army that though fighting the Ottoman Empire in World War One, the caliphate itself would be protected.  But the 1920 Treaty of Sèvres gave the holy places of Mecca and Medina to the Arabs and then as Ataturk created his own settlement, there was only go to be one father figure in Anatolia and Eastern Thrace and the West allowed the caliphate to cease to exist.
Saddam Hussein was a man of unquestionable brutality and megalomania but he always kept Iraq secular and free of religiously motivated terrorism. He was also a bulwark against Iran, even in his post-1990 pariah days.  This was another reason against invading Iraq in 2003.  Yet it happened.  The agreement for complete troop withdrawal by 2011 was signed by the Bush administration yet Obama had no plans to reverse it and took the credit.  Now he takes the brickbats for not leaving a 'stabilising force' of several thousand soldiers behind, but Iraqi prime minister Nouri al-Maliki (like the intransigent Hamid Karzai) would not hear of it because it would interfere with his desire to make Iraq a satellite of Iran.  Such a stabilising force was not in the US-Iraqi agreement signed by the representatives of the Bush administration
Of course, al-Maliki has completely mismanaged the country, emphasising sectarian difference in a state that would disintegrate if aligned on such lines.  Maybe it is not so surprising that not only has al-Maliki allowed Iranian aid to be funnelled to Assad via Iraq but also that al-Maliki is incompetent at fighting jihadists.  He spent decades in exile in the Syria of the Assads and is clearly no democrat.  He has destroyed the delicate triad federal system of Shias-Sunnis-Kurds and foolishly persecuted the 'Awakening' Sunni brigades organised by US General David Petraeus that drove out al-Qaeda after 2006.  Now, he desperately calls on the US to launch airstrikes, in ominous echoes of the French on their knees at Dien Bien Phu.  Obama should play hardball only agreeing to such direct assistance if al-Maliki restores the religious/ethnic balance - if he refuses but the jihadists continue to make gains, the US must step into Iraqi politics to urge a leader who does recognise reality, as at the moment the Iraqi parliament are choosing who will be the new prime minister.  It will almost certainly be counterproductive but there are few options available to the USA.