ISIL-TURKEY: In the Middle East, friends are also enemies, and enemies suddenly allies.
Then there is Turkey. No one really knows what it is any more. Qatar is the classic case of the friend the West no longer trusts. It is home to the US Central Command, a major investor in Britain - and allows proscribed terrorist financiers to roam its streets unhindered.
Iran is an enemy now fighting on the same side as the coalition against Isil in Iraq. But Turkey, increasingly, is a black hole, whose motivations cause bitter dispute. A member of Nato, it should be an upholder of Western values. But other Middle Eastern leaders, and the country's Kurdish minority, are seething at the apparent ease with which the Syrian revolution has become dominated by hardline Islamists - not least because of the "foreign fighters" crossing the Turkish border.
Turkey says it supports "moderate" Islamist groups - but does not say how it distinguishes between the moderates and the hardliners. In practice, numerous journalists have been able to interview Isil members in Turkey. It is hard to believe that Turkey's intelligence service cannot also track them down.
One explanation is simple: Isil's most successful enemy in Syria are the Kurds of the YPG, an offshoot of the PKK, the guerrilla group that has been fighting the Turkish state for decades. Many parts of the Turkish establishment fear that Kurdish success on one side of the border will carry over to the other.
But that is not a good enough explanation. Turkey's president, Recep Tayyip Erdogan has done more up to now to reconcile with the Kurds than any modern leader.
The more worrying possibility is that he is happy to give autonomy to Kurds when they are religious Sunni Muslims - as many are; less so when they are represented by the leftist secularists of the YPG/PKK. The fear is that such is his loathing of the undeniably bloody secularist Bashar al-Assad that he really does see Isil as worthy of support, or at least a blind eye, if they turn out to be the best means of bringing Assad down.
What he and his Nato allies will afterwards do with the jihadist menace on Europe's doorstep is a question that Turkey does not seem to want to face.