Iran and Turkey once ran the Middle East between them, their rival empires — Persian and Ottoman — coexisting in mutually restrained antagonism for centuries. The border that separates them today is one of the world's oldest, dating back to 1514. And Ankara and Tehran have regarded each other warily since Iran's 1979 Islamic revolution put it on a collision course with predominantly Muslim Turkey's Western, secular orientation and its role as a key NATO country on the frontline of the old Soviet Union. But in a development that has raised Western eyebrows, relations between Turkey's Prime Minister Recep Tayyip Erdogan and Iran's President Mahmoud Ahmadinejad have lately become almost cozy.

Erodgan recently dismissed Western anxiety over Iran's nuclear ambitions as based on "gossip." Besides, he has implied, if Israel is allowed nuclear weapons, why not Iran? Erdogan was the first world leader to congratulate Ahmedinejad on his re-election in June, …