Someone around here asked why Turkey hasn't been as effective against ISIS as it had supposedly been against the PKK. Well, first and foremost, I don't think it's fair to compare Turkey's military intervention in Syria with its counterinsurgency operations against the PKK on its own soil. For one thing, the geography is extremely different. The Turkish military is extremely familiar with the geography of southeastern Turkey, despite the rugged terrain and harsh environment. By contrast, Turkey isn't familiar with Syria's geography. Turkey still has a lot to learn in Syria.
Secondly, the PKK groups that have been fighting against the Turkish military since 2015 are primarily newly-formed, inexperienced groups that don't have a lot of game-changing weapons in their possession. ISIS, on the other hand, is very experienced. ISIS has been waging an insurgency against Iraq for more than ten bloody years. Furthermore, ISIS has a lot of anti-tank and anti-aircraft missiles at its disposal.
Lastly, ISIS has more followers than the new PKK groups. According to the International Crisis Group, the renewed conflict between the PKK and Turkey has led to the loss of 1,021 PKK fighters and 871 Turkish security personnel. It's obvious that the renewed war between the PKK and Turkey has been blown out of proportion by the media.
ISIS, on the other hand, has tens, if not hundreds, of thousands of fighters. Not all of them are active fighters. In fact, a lot of them are deliberately blending in with civilian populations right now. That's the scary thing about ISIS, in my opinion. These Salafi-jihadist terrorist groups cannot be defeated by military power alone. They must also be defeated through education and social reforms. The Middle East needs a new wave of secularization to combat the rise of religious extremism, otherwise groups like ISIS will simply morph into deadlier and stronger terrorist groups in the coming years.