Assuming that the Istanbul airport attack is the work of ISIS, I don’t understand the thinking of the Islamic State’s tacticians or strategists. For many years, the relatively mildly Islamist-leaning government of Recep Tayyip Erdogan has been far too lax toward ISIS. So what is the point, for the Islamic State, of repeatedly jabbing Turkey and Erdogan in the eye?
All it can do is bring down upon itself the wrath of the Turks, which, historically speaking, can be fierce. And Turkey, which shares a long border with Syria and Iraq, which has impressive military capacity (and belongs to NATO), and whose troops and air force capabilities are already onsite (with no need to be brought in from Europe or North America), is in excellent position to do serious damage to ISIS.
Which I suspect they’re poised to undertake.