As a presidential candidate Barack Obama stressed his willingness to meet Mahmoud Ahmadinejad and to extend a hand of peace if Iran "unclenched its fist". But with the US stepping up its efforts to isolate Iran and to gain support for a new round of biting sanctions against Tehran, and Ahmadinejad's public posturing with his Syrian counterpart and the Hezbollah leader in Damascus, is it time for the two leaders to meet?