Turkish-US relations have faced many serious stress tests over the past 50 years. The catalyst in overcoming those crises was making strategic considerations, which always underlined the dependence of the two NATO allies on each other, regardless of their differences.

These strategic considerations appear to be weakening now, as the regional priorities of President Recep Tayyip Erdogan’s Turkey and the United States no longer overlap, and in many cases conflict with each other.

That is certainly the case in Syria, where the two countries are at odds over Washington’s alliance with Syrian Kurdish groups against the Islamic State (IS). Ankara insists these groups are linked to the Kurdistan Workers Party (PKK), which has been waging a terrorist war against Turkey for over 30 years to gain independence at best or some degree of autonomy at worst.

The fact that the PKK is also considered a terrorist organization by the United States has not prevented Washington from cooperating with what Turkey says are PKK extensions in Syria, namely the Democratic Union Party (PYD) and its military wing, the People's Protection Units (YPG).