Washington (AFP) – President Joe Biden said Thursday that a “terrorist threat to the world” was removed when the head of the Islamic State blew himself up, as US special forces swooped on his Syrian hideout in an “incredibly challenging” nighttime helicopter raid. Biden said he had ordered an assault by troops rather than an air strike in order to minimize civilian casualties, even though this meant “much greater risk to our own people.” There were no US casualties. The death of Abu Ibrahim al-Hashimi al-Qurashi is the biggest setback to the IS jihadist group since his predecessor, the better-…