A UN official warned this week that an all-out military assault on Idlib, which has nearly 3 million residents, risked the potential for the worst humanitarian conflict “in the 21st century.”
Idlib also presents a terrorist threat comparable to Raqqa or Mosul, the previous strongholds of Islamic State in Syria and Iraq. The al-Qaeda linked Hayat Tahrir Al-Sham controls 60% of Idlib province and has as many as 10,000 fighters; there also are other jihadi groups and armed gangs there.