NEW YORK – As world powers meet in Geneva to begin nuclear talks with Iran, the world awaits the follow-up to the phone call between Iranian President Hassan Rouhani and US President Barack Obama after Rouhani’s visit to the United Nations General Assembly last month. That brief conversation – the first between the two countries’ presidents since 1979 – recalls the last attempt to revive bilateral diplomacy, undertaken 12 years ago by Iran’s then-President Mohammad Khatami.