President Barack Obama must contend with a far more complex political environment, beginning with the US Congress. There is widespread and understandable concern about leaving Iran with any nuclear capabilities, about the adequacy of provisions for monitoring and inspection, and about what will happen in ten or 15 or 25 years when various limits on Iran expire.
美国的不确定性更大。总统奥巴马必须应付远为更复杂的政治环境，首先就是美国国会。不难理解，大量美国人担心伊朗保留任何核实力，担心监控和调查条款是否足够，担心10年、15年或20年后各种对伊限制到期失效后会发生什么。说服国会批准最终契约并/或取消制裁绝非易事。