After years of tenuous cooperation, the two regional powers look increasingly like competitors.
Iranian President Mahmoud Ahmadinejad meets with Turkish Prime Minister Recep Tayyip Erdogan in Istanbul / Reuters
Turkey's ruling Justice and Development Party appears to be recalibrating its Iran policy and increasingly distancing itself from the more vocal support it previously gave the Iranian regime. As the two powers tussle over Syria, Iraq and other issues, analysts warn that their rivalry for leadership in the Middle East is only likely to sharpen.
But, for now, at least officially, Turkey maintains that it is still committed to maintaining its outreach to Iran and moving beyond the mutual suspicions that characterized the two countries' relations in decades past.
"We are doing our best to create the atmosphere for dialogue," one senior Turkish diplomat, speaking on condition of anonymity, told me. "Yes, we don't agree about all issues with Iran -- about what's happening in Iraq, in Syria -- but that doesn't mean we shouldn't talk with them. We are expressing our concerns and reactions with them about everything face-to-face."
Some recent statements from Turkish officials, though, suggest a more complex picture.
At a February 5 meeting of the Justice and Development Party, Deputy Prime Minister Bulent Arinc delivered a blistering critique of Iran's policy of support for Syrian President Bashar al-Assad despite the Syrian government's bloody crackdown on opposition strongholds.
"I am addressing the Islamic Republic of Iran: I do not know if you are worthy of being called Islamic," Arinc said, according to the Anatolia state news agency. "Have you said a single thing about what is happening in Syria?"
This tone represents quite a change from 2009, when Turkish President Abdullah Gül was among the first world leaders to congratulate Iranian President Mahmoud Ahmedinejad on his contested reelection, or in 2010, when Ankara put its relationship with Washington on the line by voting against Iran sanctions in the United Nations Security Council.
News coverage also comes with a sharper edge. The Turkish press has increasingly started running articles that cast suspicions on Iran's intentions in the region and in Turkey, with some recent reports and columns suggesting that the Revolutionary Guards were planning attacks inside Turkey and that Iran is smuggling weapons through the country to Syria.
Hugh Pope, Turkey project director for the Brussels-based International Crisis Group, and one of the authors of a report on Iran and Turkey to be released on February 23, believes that Ankara's more critical stance toward Iran indicates that "[t]he more hawkish faction in Ankara, the kind that thinks Iran is crossing the line in Syria and Iraq, is becoming more pronounced . . ."
Turkish Prime Minister Recep Tayyip Erdoğan "feels personally burned by the Iranians . . . " Pope commented. "Erdoğan likes to have wins and the risks he took for Iran did not pay off, either in the US or Iran."
But the two sides' mutual wariness is not always consistent. An Iranian general earlier threatened a retaliatory strike if Turkey hosted a North Atlantic Treaty Organization missile radar, but, nonetheless, Tehran has also proposed Istanbul as a possible site for another round of talks about Iran's nuclear research program.