Can we really blame Turkey? Our policy must seem confusing at best to a third party. Only a year ago we were gearing up to attack Assad; whatever the rights and wrongs of his regime this would have delighted IS. More recently one of his jets, in the act of engaging IS fighters, was downed by the Israelis -to whoops of appreciation on this forum. Yes, it had infringed their airspace but I'm sure IS were grateful anyway.