US President Donald Trump’s decision to pull out of the Iran nuclear deal has added new complications for Turkey’s two overriding quests in Syria: to see the Kurdish People's Protection Units (YPG) defeated and President Bashar al-Assad and his regime ousted. These two aims were already headed toward incompatibility in the crosscurrents that have shaped this crisis.

Turkey, determined to stand against the American-supported YPG, launched an operation against the group in January in Afrin, disregarding not just US but international disapproval.

Iran had expressed disapproval of Ankara’s Olive Branch operation in Afrin. President Hassan Rouhani has openly called for it to end and for Turkish troops to be withdrawn.

Turkey’s continuing staunch opposition to the Russian- and Iranian-backed regime, on the other hand, led to its enthusiastic support of the US-led strikes against the regime forces in April. Ankara welcomed these strikes even knowing it would anger Moscow and Tehran, with which it must tread cautiously because of its reliance on them in Syria.