The region of Idlib in northwestern Syria has been a fiefdom for jihadist forces for some time, most notably the al-Qaeda offshoot Hayat Tahrir al-Sham who rule about 60% of the region.
Russia and the Assad regime are likely to launch an offensive on Idlib very soon, but with three million people living there and many unhappy civilians, it's not as simple as wiping out extremists.
Sasha Ghosh-Siminoff tell us why the battle for Idlib will be a huge humanitarian catastrophe.