Even as Tehran signals an interest in nuclear talks, many experts have already envisioned what the world would look like if the country got nuclear weapons. It wouldn't be as dire as many fear, but it would unleash new uncertainties - and perhaps a regional arms race.
Tehran said it is ready to resume Iran nuclear talks with international powers after more than a year-long break. But it has yet to formally respond to an EU request to return to the table.
According to the IAEA's scale, the Fukushima crisis in Japan is now a 7, the most severe rating and equal with Chernobyl. But experts say the scale is deeply flawed.
Experts say the Stuxnet virus has penetrated Iran's Bushehr nuclear plant and may cause a serious disaster if the plant becomes operational.
Continuing technical challenges mean Iran is still probably 3 to 5 years away from acquiring a nuclear bomb. Diplomats should exploit that leverage.
The Stuxnet virus that attacked Iranian nuclear sites has affected some of the nuclear centrifuges, President Mahmoud Ahmadinejad said Monday.
The International Atomic Energy Agency reported Tuesday that Iran temporarily stopped nuclear enrichment this month. Experts suggest technical difficulties may be the cause.