The growing tension between Turkey and Iran over the latter’s unwavering support for embattled Syrian dictator Bashar al-Assad’s regime as well as Tehran’s engagement in clandestine activities, including terrorism, that threaten Turkey’s national security may be a harbinger of a more serious rift than currently appears in the exchange of accusations against each other.

Turkey feels that Iran has not responded to the open engagement policy of the ruling AK Party government in the last decade against nuclear-power aspirant Iran. Ankara even went to the limit in 2010 and cast an opposition vote against the UN Security Council resolution against Iran, deviating from its Western allies. Today, however, many officials in Ankara openly admit that Turkey did not gain anything from Iran, be it political or trade concessions. Instead, the mullah regime in Tehran has accelerated it efforts in thwarting the expansion of Turkish influence in a number of countries spanning the Middle East to the Horn of Africa.

It seems Ankara is resigned to the fact that Persian nationalist discourse, mixed with the radical interpretation of Shiite ideology, will not stop Iran from exploiting ethnic and sectarian divisions in Turkey’s neighborhood and will do everything to limit the maneuvering space for Turkish foreign policy. That includes supporting terror groups that wage war on Turkey such as the Kurdistan Workers’ Party (PKK). Interior Minister ?dris Naim ?ahin revealed on Tuesday that roughly half the members of the PKK killed by Turkish security forces are not Turkish citizens but rather citizens of Iran, Syria and Iraq.

The turning point in worsening ties between the two countries has been the 17-month-old Syrian crisis during which the minority Nusayris regime, backed by Iran, has been cracking down on the opposition with fatalities reaching 25,000.

Professor Birol Akgün, a specialist from the Ankara-based Institute of Strategic Thinking (SDE), argued that the crisis between Turkey and Iran may deepen depending on how events in Syria unfold. “Iran acts with sectarian motivations, which are the traits of the regime. Radicals in Iran feel that if Syria falls, that means the exterior shell of the Iranian regime will be cracked, which in turn may lead to a Persian spring,” he told Sunday’s Zaman.

Turkey has ended its silence against Iran this week against a series of unusually sharp statements coming from Iran, reversing its earlier course of keeping its protest to diplomatic channels. Turkish Prime Minister Recep Tayyip Erdo?an openly bashed Iran this week for its stand on Syria, saying that defending a regime that kills its brothers, Iran betrays Muslim values and Islamic beliefs. He was reacting to comments by Gen. Hassan Firouzabadi, who has said that “it will be its turn” if Turkey continues to “help advance the warmongering policies of the United States in Syria.”

Recalling that Turkey had been one of Iran’s few defenders amid Western pressure to boycott Iran over its nuclear program, Erdo?an said: “When no one else was by its side, Turkey was the country that stood by Iran, despite everything. Turkey was also the country that defended [its right to] nuclear energy.” Turkey’s Foreign Ministry also on Tuesday issued a strongly worded statement condemning comments made by Firouzabadi. “We strongly condemn statements full of groundless accusations and exceptionally inappropriate threats against our country by some Iranian officials,” the statement said, adding that “it is unacceptable and irresponsible that Iranian officials in various posts continue to target our country through their statements.”

Many in Turkey believe that it is hard to recover from the deepening rift between the two countries, which may spell more crises that need to be managed for the future. “Following the Turkish open position against the Assad regime in Syria, the relations between Turkey and Iran will never go back to where they were. The Syrian crisis has exposed Iran’s true face,” Suat K?n?kl?o?lu, the director of Ankara-based Center for Strategic Communication (Stratim) told Sunday’s Zaman. He said there was a Turkish romanticism in the Middle East, especially as regards to Iran, among conservative circles in Turkey.

“The shrewd Iranians always pretended they were embarking on a special relationship with Turkey. Many in Ankara were eager to believe. The Syrian crisis, among others, has exposed the true character of Iran, which is very much framed by a sectarian worldview,” K?n?kl?o?lu said, adding that “Turkey’s reintegration into its neighborhood space needs reassessment in view of the tectonic changes precipitated by the Arab Awakening.”

The problems with Iran are not just limited to Syria. The meddling of Iran into Iraqi affairs and its support of Shiite leader Nouri al-Maliki’s exclusionary policies of Sunnis and Kurds in the country drew the ire of Ankara as well, complicating already-tense ties between Turkey and Iran. Turkish Prime Minister Erdo?an criticized Iran’s support of Maliki’s government on Tuesday, saying that Maliki enjoys a good level of support from Iran in clinging to power. “It is not possible to accept Iran’s stance. We conveyed this to them at the highest level of talks. We said to them, ‘Look, this has been a source of disturbance in the region’,” Erdo?an stated.

The problems with Iran also manifest themselves in the trade and economic ties as well, with Ankara complaining about major hindrances in entering into the vast Iranian market despite numerous agreements and protocols. Many Turkish firms find it difficult to operate in Iran, whose economy is pretty much controlled by the Revolutionary Guards tied to religious leaders. The trade volume, heavily dominated by Iranian gas and oil, does not favor Turkey and contributes to the high current account deficit (CAD) Turkey maintains.

“Then, the mantra was that Iran would soon open critical sectors in its economy to Turkey. Iranian gas fields were supposedly going to be jointly operated. Bilateral trade was to reach $30 billion annually. Of course, none of that materialized. The Iranians never intended to open up to Turkish firms, which would upset internal commercial interests within the mullahcracy,” K?n?kl?o?lu asserted.

As a sign of the mounting crisis between Turkey and Iran, a recent decision by Iran to suspend a visa-free travel regime with Turkey may be a harbinger of a more serious confrontation between the two countries. For the first time since the visa-free regime went into force in 1964, Iran suspended it last week, citing security concerns in the run-up to a summit of Non-Aligned Movement (NAM) in Tehran as an excuse.

“Visa regime is a step which reflects the tensions between Iran and Turkey. Obviously, Iran’s attitude can be considered a first step for the subsequent tensions with Turkey,” Bayram Sinkaya, an expert on Iranian politics and a lecturer in the department of international relations at Y?ld?r?m Beyaz?t University in Ankara, said in remarks to Sunday’s Zaman.

Asked how much worse the ties can get between the two countries, Sinkaya said both Turkey and Iran have to manage their relationship, saying that Iran does not want to lose Turkey for fear of further isolation. The same is also true for Turkey, he said, predicting that Turkey will be more patient with the mullah regime in order not to taint the regional image.

In any case, Turkey and Iran are set to have more showdowns in their bilateral relations before reaching a new level of understanding on resolving their differences.