[IS] is certainly weakening, but this is largely because the war has been internationalised since 2014 by US and Russian military intervention. Local and regional powers count for less than they did. The Iraqi and Syrian armies, the YPG and the Peshmerga can win victories over IS thanks to close and massive air support. They can defeat it in battle and can probably take the cities it still rules, but none of them will be able fully to achieve their war aims without the continued backing of a great power. Once the caliphate is gone, however, the central governments in Baghdad and Damascus may grow stronger again. The Kurds wonder if they will then be at risk of losing all the gains they have made in the war against Islamic State.

To read the rest of the article, visit the London Review of Books.