As world powers meet in Geneva to begin nuclear talks with Iran, the world awaits the followup to the phone call between Iranian President Hassan Rouhani and U.S. 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. In both episodes, a missing handshake symbolized the countries' persistent rift.

Back then, Khatami and Foreign Minister Kamal Kharrazi "went shopping," rather than attend a cultural event at the Asia Society and risk crossing paths — and shaking hands — with U.S. Secretary of State Madeleine Albright.