(Note: the below comes from my previous Canary article here.)
- Very real frustrations with the Assad regime escalated into civil war in 2011. The interference of Assad’s regional and international foes (Turkey included) contributed to this, as did the regime’s own authoritarian response to protests.
- The Syrian government dug in and the anti-Assad opposition (sponsored by Turkey and other Western allies) became dominated by Daesh and other jihadi forces.
- Fighting against Daesh soon became the (stated) focus of Western intervention in Syria, and deposing Assad became less of a priority.
- The most effective opponents of Daesh, in northern Syria at least, were the progressive Kurdish-led YPG/YPJ of Rojava. Western allies in the region had isolated these forces for years, but they gained international media attention because of their resistance to Daesh. So the West gave them limited strategic support in this fight from late 2014 onwards.
- The Turkish regime, which was soon cracking down on Kurdish rights and democratic opposition at home, became increasingly frustrated with YPG/YPJ-led successes (which it feared would boost the pro-democracy cause in Turkey), along with its own failing efforts to oust Assad. So it shifted its priorities to focus on fighting the YPG/YPJ, and invaded Syria in late August 2016.
- The YPG/YPJ and their allies defeated Daesh in Raqqa in late 2017. And with Daesh effectively out of the way, the West had little use for the YPG/YPJ and allowed Turkey to launch a cross-border attack on them in January 2018.
In short, Turkish involvement has been a given at every stage of Syria’s conflict.