Solid opening:
The Arab Spring has heightened the ideological tension between Ankara and Tehran, and Turkey's model seems to be winning. Last spring, Iran often claimed that the Arab revolutions were akin to the Iranian one decades before and would usher in similar governments. Yet in Tunisia and Egypt, for the first time, leading figures in mainstream Islamist parties have won elections by explicitly appealing to the "the Turkish model" rather than to an Iranian-style theocracy. What's more, in December 2011, the Palestinian movement Hamas salted the wound when a spokesman announced the organization's shift toward "a policy of nonviolent resistance," which reflected its decision to distance itself from Syria and Iran and to move closer to Egypt, Turkey, and Qatar.
The clash between Turkey and Iran has been more than just rhetorical. Tehran has been Syrian President Bashar al-Assad's biggest supporter, whereas Ankara has come to condemn the regime's "barbarism" and put its weight behind the opposition, hosting the Syrian National Council and the Free Syrian Army, the rebel government and army in exile. In Iraq, Iran is a patron of the Shias; Turkey is, at least in the eyes of many in the Middle East, the political and economic benefactor of the Sunnis and the Kurds. And the two countries have had tensions over the missile shield that NATO deployed in Turkey in September 2011. The Turkish government insists that the missile shield was not developed as a protection against Iran. Nevertheless, in December, an Iranian political official warned that his country would attack Turkey if the United States or Israel attacked Iran.
The rest can be found at Foreign Affairs.