Britain faces a renewed and chilling terror threat as battle-hardened ISIS fighters risk slipping into Europe amid chaos in northeastern Syria, The Telegraph warns. More than 10,000 ISIS militants remain detained in fragile prisons and camps like Al-Hol, as clashes between Syrian forces and Kurdish-led SDF raise fears of mass jailbreaks. Intelligence sources warn radicalized fighters and children could fuel future attacks across the West. As the U.S. rushes detainees to Iraq to prevent catastrophe, concerns mount over UK-linked ISIS families, Shamima Begum, and the wider implications for European security.