The siege of Mosul and targeted killings of chemical weapons experts in U.S.-led coalition airstrikes have significantly degraded the Islamic State’s production capability, a London-based analysis group said Tuesday, The Associated Press reported. However, IHS Markit said IS likely retains the expertise to produce small batches of sulfur mustard and chlorine agents. In a new report, IHS Markit said there has been a major reduction in IS’ use of chemical weapons outside Mosul. It has recorded one alleged use of chemical weapons by the group in Syria this year, as opposed to 13 allegations in the previous six months. All other recorded allegations of IS using chemical agents in 2017 have been…