Turkey is emerging as a key player both in the future of Syria's revolution and the next round of talks over Iran's nuclear program. On Sunday there will be another meeting of the "Friends of Syria" in Istanbul and it seems increasingly likely that the Turkish city will be the venue of the P5+1 talks with Iran two weeks later.

Reccep Tayip Erdogan visited Iran this week and behind the smiles and hand-shakes, the deep split opening up between the two countries over the survival of Basher Assad's regime was hard to hide. In a meeting on Thursday with Supreme Leader Ayatollah Ali Khamenei in Masshad, Khamenei warned that "the Islamic Republic of Iran will defend Syria due to its (Syria’s) support for the line of resistance against the Zionist regime and is strongly opposed to any intervention by foreign forces in Syria’s internal affairs.” Erdogan's response was not recorded in any of the reports of the meeting but in an interview with Iranian state television he said that all parties "should respect the will of the Syrian nation." The foreign nation currently intervening most blatantly in Syria's affairs is Turkey and at the conference in Istanbul on Sunday, Erdogan's government plans to announce that the Syrian National Council (SNC) is from now to be regarded "principal representative" of the Syrian people. Over the last few months, Ankara has managed to elevate the SNC, an opposition grouping comprised mainly by Muslim Brotherhood members, though it has also some secular representatives, mainly to improve its image in the west, as the main opposition group to the Assad regime.

There could be no clearer challenge to Iran's intention to ensure the future of its ally in Damascus. Reinforcing this message was a publicized visit on Wednesday by Turkish Army Land Forces Commander Gen. Hayri Kıvrıkoğlu to his troops on the Syrian border. Defense Minister İsmet Yılmaz said later that it was just a routine inspection and that Turkey was not a threat of military action but the visit was widely seen as another step towards the possibility of Turkish troops entering Syrian territory to create a safe "buffer-zone" for refugees from the Idlib, Hama and Homs regions where hundreds of civilians have been killed by the Syrian security forces in recent weeks. At least 18 thousand refugees have already crossed the border into Turkey.

The entrance of Turkish troops would be a major blow to the regime which is still holding on, over a year after the revolution began. It could lead to direct clashes with the Syrian army and perhaps even with Iranian officers who have been widely reported to be supporting the Syrian forces. Even if Turkey does not create a buffer-zone, it is already deeply involved within Syria through its support for the SNC and by providing it a base, a clear challenge to Iran's policy.

On the other hand, Erdogan did have some carrots for his Iranian hosts, promising to boost bilateral economic ties between the two countries, totally disregarding the international sanctions on Iran and reiterating in his meeting with President Mahmoud Ahmadinejad that "The government and nation of Turkey has always clearly supported the nuclear positions of the Islamic republic of Iran, and will continue to firmly follow the same policy in the future."

By hosting the talks between Iran and the five permanent Security Council members (and Germany), Erdogan is staking his international statesmanship credentials on achieving a diplomatic breakthrough, which can only be reached through Iranian concessions on sweeping powers for IAEA experts to carry out surprise inspections at nuclear sites. He now has a unique pressure-point over the Iranians – allow inspections or lose your Syrian ally.