US airplanes have resumed operations against Isis from Turkey but the upheaval has shown how at odds the nominal allies are

US airplanes have resumed operations in the fight against Islamic State after being grounded for two days at an airbase in southern Turkey amid uncertainty over what the countrys failed takeover might mean for bilateral ties and for the war itself.

The early signs were confounding. While Barack Obama spoke out in support of his counterpart, Recep Tayyip Erdoan, as Friday nights plot unfolded, dialogue since has underlined a mistrust that has plagued the fight against Isis and left two nominal allies once again struggling to find common ground.

Erdoans demands that his foe, Fethullah Glen, in self-imposed exile in the US, be extradited over claims that he drove the plot, were perceived as a slight in Washington. Officials speedily disavowed links to Glen, demanded evidence of any connections, and rejected an implication that the US itself may have been involved.

Before the Incirlik airbase reopened, Turkish authorities arrested the basis commander, Gen Bekir Ercan Van, and 11 other suspects, claiming they were involved in the attempted coup.

It is the latest in a series of incidents that have undermined relations between Ankara and Washington since the US-led air campaign against Isis began in late 2014.

Despite both sides claiming a mutual interest in combating the group, which had overrun large parts of Syria and Iraq and was starting to incite terror farther afield, it took the US 11 months of negotiations to gain access to Incirlik, which is near the Syrian border.

Washington had made clear that the use of Incirlik would greatly aid the fight against the terrorist group. Turkey had countered that dealing with Kurds in northern Syria was just as important to its own interests. In the months since, US officials have come to believe that Turkeys concerns about the Kurds hold primacy.

Turkish officials have railed against US moves to use Syrian Kurdish units as a proxy ground force-out to fighting Isis and have bitterly opposed the alliance, even as it has stripped land from different groups near its Syrian hub of Raqqa.

Kurdish peshmerga soldier stands next to suspected Islamic State fighters in Iraq on Friday. Photograph: AP

Rarely have two nominal friends been at such odds over such essential matters. To Turkey, the Syrian Kurdish cooperation has an asking price the advancement of territorial ambitions, which it believes play immediately to the restive Kurdish minority within its borders.

To the US, a failure to defeat Isis would even further destabilise the region and could pose an existential menace to its allies, especially now that the group is actively exporting chaos to Europe and beyond.

As Erdoan continues to crack down on those he alleges were responsible for the takeover and tackle other perceived menaces affecting up to 5,000 military officers and troops and close to 3,000 magistrates in so far Turkeys allies are bracing for further demands from an emboldened leader.

Hard-won Turkish cooperation against Isis had begun to bear fruit in recent months, with US and allied planes now much closer to the action and able to more directly support operations led by the Kurds in north-east Syria. There, the town of Minbij, roughly halfway between Raqqa and Isiss easternmost stronghold of al-Bab, remains under assault. Its autumn would cut a key supply line, stiffening the noose on Raqqa, as Iraqi forces-out edge towards Mosul.

Isis has launched four large-scale attacks on Turkish clay in the past 18 months, the most recent of which was a triple suicide bombing at Ataturk airport in Istanbul last month. Over the same period, Ankara has cracked down on those travelling to join Isis, denying suspected militants entry to the country and patrolling its 500 -mile border with Syria with vigour.

The US and UK believe the attacks have brought the requirements and Ankaras closer together. But there has been no compromise on Turkish demands that the Kurds not be rewarded for their cooperation in the fight.

Concerns about Kurdish aspirations were a key factor in a detente agrees with Ankara and Moscow this month, after an eight-month stalemate which followed the Turkish downing of a Russian fighter over northern Syria. Turkey had accused Russian airplanes of bombing its friends fighting the Assad regime inside Syria, and the conflict seemed unlikely to be solved soon.

However, both sides share a common view that Syrias territorial integrity should not be compromised by whatever emerges from the wreckings. According to Turkish officials, Erdoan has also calculated that Vladimir Putin has more capacity to deliver outcomes in Syria and the broader region than the outgoing Obama, who has defined US interests through a narrow prism of defeating Isis.

Before the failed takeover, Erdoan believed he was close to being alone in the fight against Assad and stone-cold alone with his concerns about the Syrian Kurds. He has now found an friend in the latter cause and, empowered by popular support, appears to be in a stronger position to demand cooperation on the former.

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