The most difficult might be the timing of when various economic sanctions are to be removed – the issue of greatest concern to Iran. But these same sanctions are also the source of the greatest leverage over Iranian behavior, which means that many in the US and Europe will want them to remain in place until Iran has fully met its critical obligations.
第二个原因来自悬而未决的具体问题。最困难的问题要数各种经济制裁何时取消——这也是伊朗最关注的问题。但这些制裁正是约束伊朗行为的最大武器，这意味着许多美国和欧洲人希望保持这些制裁措施直到伊朗充分履行关键义务。