Isis are "clearly deteriorating" but the battle against them is far from over.
This is according to Chatham House Middle East spokesman Tim Eaton, who spoke to talkRADIO after Isis fell back to Mosul. The group has been giving ground for months, harried by Iraqi ground forces and US airstrikes.
"Over time, we've seen a considerable deterioration and breakdown in Isis's ability to continue the fight," he told Julia Hartley-Brewer. "But we shouldn't be fooled by the square miles - at the end of the day, it's population centres that matter.
"Most of the areas lost are spaces that are largely deserted or sparsly populated. They continue to hold significant centres like Mosul, although this is coming under threat now.
"They seek to operate as a state, and they seek to govern. When the people who do that are taken out, it has an effect, so it's clear to say that Isis are deteriorating."