The town of Kobani, a Kurdish enclave near Syria's border with Turkey, has become an important flashpoint in the United States-led campaign against the militants of the so-called Islamic State (IS). Despite US airstrikes, the militants have taken control of one third of the town, one of three enclaves declared autonomous by Syrian Kurds two years ago. US military commanders fear that IS fighters cannot be driven out of Kobani without the use of ground forces – and there is no question of US ground troops being deployed.
Just across the border from Kobani, Turkish tanks are within striking distance but Turkey – although officially part of the anti-IS coalition – is refusing to help. The government of President Recep Tayyip Erdogan is also preventing Kurdish fighters from crossing from Turkey into Syria to support the struggle against IS.
The US and its allies are outraged by Turkey's refusal to act, but Mr Erdogan and his equally stubborn prime minister Ahmet Davotuglu have ignored all entreaties to change course. This reflects the fact that for Turkey, the overthrow of Syria's President Bashar al-Assad remains a much more important objective than defeating IS. Ankara wants the Syrian Kurds, allies of the Kurdistan Workers Party (PKK) – who are engaged in peace talks with the Turkish government after a long guerrilla campaign – to join the fight to topple Assad. Mr Erdogan has signalled that Turkey will not take significant action against IS until Washington shows that it has a plan to weaken Assad as well as to push back the militants.
It is a dangerous game that has already provoked violent protests from Turkey’s Kurdish minority. Turkey’s inaction risks increasing its exposure to IS, which already controls half of its 820-km border with Syria and increasing yet further the huge number of Syrian refugees in Turkey. The stand-off over Kobani also highlights the confusion at the heart of the campaign against IS, which needs to complement military action with a more robust diplomatic track aimed at ending Syria’s civil war.