Don't let the religious angle get in the way - what Turkey is and isn't doing is all down to Erdogan and related interests being very dangerous and power crazed.

Turkey wants to see the back of Assad and Syria as a functioning state - it's been arming the Syrian "rebels" for ages and there are strong rumours that Turkey was involved in the Chemical Weapons attack that was briefly in the news a while back until evidence mounted that it wasn't carried out by Assad's regime. Turkey has no interest in attacking IS outside of its own borders, as IS are part of the plan to eliminate Assad and Syria.

Erdogan has it in for the Kurds big style and there are again very strong rumours that the bombing of a Kuridsh rally in Turkey was state-sponsored.

Erdogan is also looking for re-election and to increase presidential powers even further, so looking hard to the electorate is a key strategy too.

Nothing to do with religion.