The camps where they are held pose a formidable security and humanitarian challenge to the region.
Western governments should, at minimum, accelerate the repatriation of women and children.
Alongside the thousands of foreign fighters detained in north east Syria are thousands of non-Syrian children and women.
Western governments have for months publicly wrestled with political and policy qualms about repatriating their nationals.
Turkey’s incursion into Syria highlights that the window for repatriation or transfer could close suddenly.
Why does it matter?