A quite interesting summary of the challenges associated with the Iranian nuclear program has been written by Gregory Jones, and released by NPEC. Some key points:
- The Iranian production rate of reactor-grade enriched fuel has been increasing, not decreasing.
- The conversion of fuel grade to 20% enrichment levels for "research" purposes has been allowed, and not considered a violation of Iran's responsibilities as a signatory to the Nuclear Nonproliferation Treaty.
- Because most of work required to enrich uranium is expended at low concentrations, going from a 20% enrichment level to the 90% level needed for bomb-grade is relatively minor. Jones estimates it would take only two weeks. While this step would constitute a violation of the NPT, there would be little lead time to do anything about it. Jones argues that while Iran also needs to develop a weapon in which to use the bomb-grade material, much of that process could be done in parallel. Bottom line: the cover provided by a wildly uneconomic civilian power program in Iran has eliminated most of the leadtime to produce a bomb.