FACE TO FACE: Iran and six world powers are scheduled to meet this week in hopes of ending a decade of deadlock on Tehran's nuclear program.
DETENTE?: Chances for progress have seldom been better following the June election of Iranian President Hassan Rouhani and then last month's phone call between him and President Obama — the first conversation between Iranian and U.S. leaders in more than three decades.
WHAT'S SOUGHT: For the U.S. and its allies, the ideal solution would be for Tehran to scale back aspects of its nuclear program that many nations fear could aid in making a bomb. That would trigger a gradual lifting of the economic sanctions on Iran.