One of the striking discoveries while researching the NATO book was the case of Turkey. Turkey had very restrictive rules of engagement--it was unwilling to engage in offensive operations. It only lost soldiers due to a helicopter crash. They did let their soldiers engage in offensive operations if they were embedded in an Afghan army unit, but that was the extent of it. The basic claim was that they didn't kill Muslims.
Why is this surprising? Well, unlike Germany, where pacifism is a key domestic political challenge, Turkey is not that reluctant to use force.... against Kurds (many of whom are Muslim). As the world puts increased pressure on Turkey to help the Kurds of Syria, Turkey responds by dropping bombs on its own Kurds. This nicely illustrates the priorities Prime Minister Erdogan has, but this is not that new either.
On the other hand, this is not a very nice reality. It should not be that surprising either. Galling perhaps, but not surprising. Turkey has felt under-supported by NATO as the frontline state facing Syrian (Assad, that is) attacks across the border, the brunt of the refugees and all that. Turkey's priority is Assad and the Kurds with ISIS in third place... maybe.
While I have argued elsewhere we should not overly bash Turkey, and that we need to take seriously the context, this bombing of Kurd positions in Turkey while it refuses to do much to help out in Syria is a bit of a finger in the face of the international community. So, yeah, we can direct some umbrage at Turkey, not that it will matter much.
As I have said before, alliances are hard... as countries have their own interests.