Maggie's Farm

Although the operation is primarily seen as a threat to the Kurds it also poses considerable risks to Erdogan. "Turkey’s intervention in northern Syria inspired domestic support for the country’s armed forces, but also skepticism, fear and anger in a politically divided country that perceives it has already suffered greatly because of the continuing eight-year conflict to its southeast. But the president’s Syria policies have also begun to badly hurt him and his allies politically, as economic troubles exacerbate long-simmering Turkish animosity towards Arabic-speaking Syrians."

In other words Syria risks becoming Erdogan's Vietnam. The Independent writes:

Turkey is already fighting a guerilla war against the separatist Kurdistan Workers Party (PKK) in its own southeast provinces. Expanding the ground war into Syria against the PKK’s allies risks sparking a separate insurgency. The Syrian Democratic Forces, the collection of Kurdish-led armed groups partnered with the US in its fight against Isis, said it was “determined to defend our land at all costs” against Turkey.

“What makes Turkey think they’re not going to get caught in northern Syria fighting a protracted campaign?” said Steven Cook, a Turkey and Middle East specialist at the Council on Foreign Relations. ... “They’re really exposed going deeper into Syrian territory,” said Mr Cook. “And they’re not going to get any help. If Erdogan gets into trouble, the cavalry is not coming to the rescue.”