TEHRAN, Iran — What’s going on between Iran and Turkey? Questions are being raised by allies before enemies. The two neighboring, former Islamic empires were thought to be parting with many of their differences over the Syrian crisis, which both regard as a foreign policy priority. Day after day there are indications that Ankara and Iran are heading slowly but surely toward strategic relations, which could result in the countries signing what a source in Tehran described as a “strategic cooperation treaty.”

Turkish Prime Minister Recep Tayyip Erdogan is expected in Tehran within two weeks. Meanwhile, both countries’ foreign ministers exchanged visits within a short time period; Iranian Foreign Minister Mohammad Javad Zarif visited Turkey on Jan. 4, while Turkish Foreign Minister Ahmet Davutoglu was in Tehran a week earlier. As these words are written, Iranian Undersecretary for Arab and African Affairs Hussein Amir Abdulahyan is in Ankara to meet his counterpart. These meetings reflect a high level of coordination between Iran and Turkey. Yet some will ask, what about their differences over Syria?

There’s no doubt that the Syrian crisis rattled the harmony that once brought together Tehran, Ankara, Doha and Damascus, but this meant nothing to Iran’s cooperation with Turkey on a different front. A source in Tehran told Al-Monitor that security officials of both countries met frequently and shared information vital to national security. “There was cooperation, even in Syria. On several occasions Turkish and Iranian mutual efforts helped in releasing kidnapped personnel from both countries. There might be differences in the political goals, but on the security front both countries share the same objectives and won’t do anything that harms the other’s interests.”

It’s not just politics and security, the economy plays an important role in bilateral relations. Erdogan is still paying the price for the black holes he’s accused of creating in the sanction system on Iran, specifically what’s known as the gold-for-oil scheme. At least $20 billion was exchanged in trade between the two countries in 2012, and this figure is expected to increase now that some sanctions on Iran are to be loosened.