You can't defeat the PKK by military force alone.
If you truly want to defeat the PKK, then you must grant more cultural and political rights to the Kurdish minority, otherwise the PKK leaders will always exploit the grievances of ethnic Kurds who feel marginalized by the Turkish government.
As long as Turkey continues to think the solution to bloodshed is more bloodshed, then nothing will be solved. On the contrary, the situation will continue to deteriorate, and Turkey will be held back from reaching its economic potential.
As for ISIS terrorism, the Turkish government must be more genuine in the fight against extremism. The AKP is still turning a blind eye to many radical Muslim preachers in Turkey, not to mention turning a blind eye to radical Islamic militant groups in Syria. As long as these suicidal policies persist, the ISIS threat will always remain.
Turkey can still solve all these problems on its own, but the country is running out of time.