When the Syrian civil war broke out in 2011, Turkey was one of the earliest countries to invest heavily in the overthrow of the Assad regime. Despite a decade of warming relations with Syria, President Recep Tayyip Erdogan was making a bid to become the region’s dominant power. The situation in Syria has since changed dramatically—but the Erdogan strategy has not.

The result is that Turkey has become a barrier to resolving the conflict. It wages war on the Syrian Kurds, Islamic State’s most effective opponents. And the country now plays host to an elaborate network of jihadists, including ISIS.

Early on, Turkey wanted to foster a Sunni majority government in Syria, preferably run by the local branch of the Muslim Brotherhood. This would deprive Turkey’s two historical rivals, Russia and Iran, of an important client state, while allowing it to gain one of its own.

The plan was simple and elegant. But the Assad regime proved more resilient than expected, and the West refused to intervene and deliver a coup de grâce. So-called moderate Syrian rebels have either been sidelined by Islamist militants, or revealed to have been Islamist militants themselves. Thanks to Islamic State, the war has spread to engulf half of Iraq. And yet, as a global consensus solidified about the importance of defeating ISIS, Turkey has continued to play the game as if it were 2011.

This summer, for example, the Erdogan government came to an important agreement to let the U.S. use two of its air bases for strikes against ISIS. Yet Turkey has used the same bases to attack Kurdish forces in Iraq and Syria. The Erdogan government remains more concerned with limiting the power of the Kurds in Syria than with defeating ISIS.