We do not have sufficient intelligence reporting to judge confidently whether Tehran is willing to maintain indefinitely the halt of its previously enumerated nuclear weapons-related activities while it weighs its options, or whether it will or already has set specific deadlines or criteria that will prompt it to restart those activities. We assess Iran has the scientific, technical, and industrial capacity eventually to produce nuclear weapons. In our judgment, only an Iranian political decision to abandon a nuclear weapons objective would plausibly keep Iran from eventually producing nuclear weapons—and such a decision is inherently reversible. I reiterate that two activities of the three relevant to a nuclear weapons capability continue: development of uranium enrichment technology that will enable production of fissile material, if Iran chooses to do so, and development of nuclear-capable ballistic missile systems.
We assess convincing the Iranian leadership to forgo the eventual development of nuclear weapons will be difficult given the linkage many within the leadership see between nuclear weapons and Iran’s key national security and foreign policy objectives, and given Iran’s considerable effort from at least the late 1980s to 2003 to develop such weapons. Our analysis suggests that some combination of threats of intensified international scrutiny and pressures, along with opportunities for Iran to achieve its security and goals might—if perceived by Iran’s leaders as credible—prompt Tehran to extend the halt to the above nuclear weapons-related activities. It is difficult to specify what such a combination might be.
I'd call that an understatement. More here.