ISTANBUL ― Iranian President Hassan Rouhani’s charm offensive has stalled. It worked well in the United Nations General Assembly last September, when he had something solid to offer ― a deal on his country’s nuclear program ― raising hopes that Iran’s hardline foreign-policy stance would finally soften. But U.N. Secretary-General Ban Ki-moon’s withdrawal of Iran’s invitation to the Geneva II conference on Syria suggests that Rouhani will need more than charm ― or even a visit by Turkish Prime Minister Recep Tayyip Erdogan to Tehran ― to end his country’s isolation.

Rouhani has been largely successful in putting his predecessor Mahmoud Ahmadinejad’s tone-deaf leadership firmly in the past. The Iranian establishment has supported his attempts to open the country up to its regional neighbors, court foreign investment, call for moderation in religious and cultural matters, and even pursue the nuclear deal with the West.

In fact, the nuclear agreement ― which seems close to completion ― is likely to be Iran’s most important diplomatic achievement since the Islamic Revolution in 1979, providing it with considerable relief both domestically and internationally. The fact that Supreme Leader Ayatollah Ali Khamenei personally backed the effort makes it all the more promising.

Nonetheless, the regime’s possible rapprochement with the United States remains a source of concern in the Middle East, because it would empower Iran at a time when the U.S. is gradually disengaging from the region. The question now is whether Rouhani’s moderation toward the West will be accompanied by a change in Iran’s Middle East policy, with all eyes on its policy toward Syria.

Ban rescinded Iran’s invitation to Geneva II under pressure from the U.S. and the Syrian opposition. After all, since the civil war began in 2011, Iran has provided essential financial and military support for Syrian President Bashar al-Assad’s regime, while mobilizing its Lebanese proxy, the powerful Hezbollah militia, to fight against the rebels in Syria.

Whatever concerns the opposition has about Iran’s allegiances, the country is undoubtedly part of the Syrian equation; indeed, its involvement is critical to reaching any accord. But Rouhani’s failure to make a decisive statement on Syria ― even after a series of leaked photographs of systematic torture and massacre raised the ire of the international community ― has not helped the case for keeping Iran in the fold.

Rouhani recently had an opportunity to discuss Iran’s stance. But, addressing the World Economic Forum in Davos, he squandered it, sticking to platitudes about the need for governments in the region to listen to their citizens and provide young people with “jobs and hope.” On the subject of despotic rulers, Rouhani offered only the benign observation that they lack the ability to connect with and understand their people.

Rouhani’s recent rhetoric, however positive, falls far short of the expectations that his diplomacy has raised since his U.N. address last September. In Davos, the world expected a decisive statement on Syria and other regional problems ― not hackneyed nationalist rhetoric about eliminating “biases” against Iran.

Rouhani must have known that his failure to address the humanitarian disaster in Syria would damage his diplomatic strategy, which suggests that he must have had a strong reason. Two possibilities stand out: either there is no consensus within the Iranian elite for a policy change, or the elite remain united in their determination to continue backing Assad. Neither alternative is particularly charming, which would explain why he preferred to obscure his country’s position.

To be sure, Erdogan’s visit to Tehran this week could help to defuse tensions over Syria ― a subject on which Turkey and Iran have diametrically opposing views. But it is unlikely to smooth the divisions among Iran’s elite, much less convince hardliners to stop backing Assad, leaving the visit’s significance uncertain, at best.

In refusing to take a strong position on Syria, Rouhani ― like so many other world leaders ― is placing his own interests above those of the 2.3 million registered Syrian refugees, the millions more who have been internally displaced, the estimated 130,000 people killed, and the rest of Syria’s long-suffering population. Worse, he has refused to acknowledge Iran’s own role in the tragedy. When he said in Davos, “we cannot be indifferent to the pain and suffering of our fellow brethren in the region,” he might as well have been referring to the Assad regime and its partners in crime.

What Syria needs is not rhetoric or charisma; it needs action. Iran appears incapable of providing it. That is why Rouhani’s charm offensive will not be enough to persuade Iran’s adversaries that the Islamic Republic is ready to come in from the cold.

By Bulent Aras

Bulent Aras is global fellow at the Wilson Center in Washington, D.C. and a professor of international relations at Sabancı University in Istanbul. ― Ed.

(Project Syndicate)