Huge hurdles in path of final Iran nuke deal

VIENNA — It took months of arduous bargaining before Iran and six world powers could agree on a first-step nuclear deal. But the two sides may find the going even tougher Tuesday, when they start to confront hurdles standing in the path of a final accord.

Tehran denies Western accusations that it wants — or worked on — nuclear arms. But on Nov. 24 it agreed to initial curbs on uranium enrichment — which can serve at different levels as the core of nuclear arms or reactor fuel — in exchange for some easing of the sanctions choking its economy.