ESFAHAN, Iran — Turkey and Iran, and their predecessor states, have not engaged in war or violated each other’s borders since the 1639 Treaty of Qasr-e Shirin signed between the Safavid and Ottoman Empires.

Every now and then, and especially when Turkey’s secular parties have been in power, the two nations have had differing views on the Kurdistan Workers Party (PKK) or the Islamist groups in Turkey. However, these tensions have always subsided quickly. When the Islamists came into power, there appeared to be a warming of political ties. For instance, the $23 billion gas pipeline deal between Tehran and Ankara is the legacy of former Turkish Prime Minister Necmettin Erbakan (1996-97), who was an Islamist. Indeed, with the coming to power of Turkey’s Justice and Development Party in 2002, bilateral relations soared to an unprecedented level. However, once the crisis in Syria emerged in March 2011, things took a turn for the worse.

At first, both countries tried to not let the situation in Syria influence their bilateral relations — but unfortunately, it did. Indeed, the worsening of the situations in Syria and Iraq amid the rise of the Islamic State (IS) all appear to have fertilized the growth of tension. The question now is where the verbal disputes between Iran and Turkey may lead.

After seeing their relations strained over Syria, Turkey and Iran also engaged in a verbal disagreement over the crisis in Yemen. The two countries lined up on opposing fronts, with Tehran backing Yemen’s Houthi fighters and Ankara backing Saudi Arabia. Turkish President Recep Tayyip Erdogan accused Iran of trying to dominate the Middle East and said Iran’s efforts had begun to annoy both Turkey and its Arab allies. Following these events, a group of 65 Iranian parliamentarians called on Iran’s President Hassan Rouhani to demand an end to Erdogan’s accusations.