Syria's civil war has dragged on for five years, killing hundreds of thousands and turning millions more into refugees. UN-sponsored peace talks were scheduled to start today, but they've been delayed until Friday. Iran, Saudi Arabia, Turkey and other regional powers disagree about which rebels should be at the table. Russia still supports President al-Assad. The Obama administration says Assad must go, but is resisting calls for military action. Is it time for the US to assert its Superpower status or pursue continued restraint in a multi-polar world.