Blaise Misztal writes:
The recent interim deal with Iran has been variously described as “halting,” “freezing” and even “rolling back” Iran’s nuclear program. These terms, however, are a mischaracterization. Not only does Iran continue to accumulate enriched uranium under the interim deal, but it is actually possible for Iran to progress closer to an undetectable nuclear weapons capability without violating the terms of the agreement. Slowing the acceleration of most, but not all, aspects of Iran’s progress towards nuclear capability would be a more accurate characterization of the deal struck in Geneva.
Iran already has all the technology and materials to produce enough weapons-grade uranium for a nuclear bomb—about 20 kilograms of uranium enriched above 90 percent, known as highly-enriched uranium (HEU). But if Iran had tried to do so before signing this deal, it would have needed about two months to complete the work. Before it could finish, however, inspectors for the International Atomic Energy Agency (IAEA), who visit Iran’s nuclear facilities at least every two weeks, if not more often, would have noticed what the Iranians were doing and allowed the United States and its allies to intervene.
The time Iran would need to produce 20 kilograms of HEU—often referred to as its breakout timing—has been steadily dropping as Iran has advanced its nuclear weapons program. In fact, most analysts expected that by mid-2014 Iran would have achieved anundetectable nuclear weapons capability–the ability to breakout in less than a month, faster than it could practically be detected and stopped. (More on why this capability is significant, and tantamount to having a nuclear weapon, here.)
Whole thing here.