Why Is Turkey Still So Reluctant to Join the Coalition Against the “Islamic State”?

Over the past few months, Western allies have criticized Turkey for its ambiguous policies toward the jihadist forces in Syria and Iraq. Preoccupied by the Syrian crisis and desperate to topple Bashar al-Assad, Turkey has adopted a “blind eye” policy toward several jihadist organizations like the Jabhat al-Nusra and the Islamic State in Iraq and Syria (ISIS), after having supported the moderate opposition..