Bashar Al-Assad's forces are going to start a big campaign to re-capture the rebel-regime last province of Idlib. The campaign does not start - there is a fear of the widespread civilian casualties of Western nations and international relief agencies, including the United Nations.
Their worries, bloody wounds will erupt in the Battle of Idlib. Especially there are concerns in Turkey.
One of the primary reasons for this - thousands of civilians will start fleeing Eidlib when the campaign starts and their pressure will be controlled by Turkey. But this is not the reason for Turkey's concern, but it has a lot of military and strategic estimates.
Complicated all strategic estimates:
Syria has been involved in this proxy war and more than one country including Turkey and the superpower. Support behind the different rebel groups is cooperating with a complex network of regional-international power. They have conflicting interests