Erdogan's gambit: Could Turkey's president make peace with PKK?

In case you haven’t heard, it’s a volatile world these days. While Europe wonders if it’s just lost its US security umbrella, while a Gaza ceasefire hangs by a thread, while Syria figures out how to hold it together after the fall of Assad; major regional player Turkey looks to get its own house in order with the announced dissolution of a 40-year old Kurdish insurgency. Why did Recep Tayep Erdogan and imprisoned PKK leader Abdullah Ocalan agree to open a path to peace? Why now?