Turkey wants to control Syria, it’s their first step to reforming The Ottoman Empire.
Iran wants Syria, too. Russia is friends with Iran.
Finally. Somebody who "gets it".
Buying stolen oil from ISIS ---- Turkish traders made off like bandits, and ISIS well lubed with cash to harass Syrian government forces, and any [ahem] moderates (anyone milder than screaming Islamacists).
Erdogan is the devil. Ok, he's just the devil's spawn. Close enough.