Report: Iran capable of quickly enriching uranium for warhead

Iran has the capacity to enrich enough weapons-grade uranium for a nuclear warhead in two to four months' time, a think tank reported Monday. 

But the Institute for Science and International Security (ISIS) said it would take "many additional months" for Iran to manufacture a nuclear device suitable for underground testing, and even longer to make a warhead for a ballistic missile.

“If Iran were to attempt to make a nuclear weapon, it would likely face new engineering challenges, despite work it may have done in the past,” the ISIS report said.

ISIS said Iran’s breakout time to produce weapons-grade uranium for a bomb is decreasing as it continues to step up production of 20 percent low-enriched uranium and build up its underground Fordo plant. 

Still, the group argues Iran is unlikely to take the step to produce the higher-grade uranium next year because the production would almost certainly be detected by the United States and other countries.

“These sites are monitored by the [International Atomic Energy Agency] IAEA and closely followed by U.S. and other intelligence agencies, meaning that Iranian production of [weapons-grade uranium] could not evade detection,” the report says.

“Iran’s potential nuclear weapons capabilities are growing, but Iran could not yet break out without avoiding detection by the IAEA or the United States,” the report says.

U.S. officials have said they do not believe Iran has made a decision yet to move forward and build nuclear weapons.

Iran insists its nuclear program is for peaceful purposes, but the United States and its allies suspect Iran is considering building a nuclear bomb.

President Obama has said no option is off the table to stop Iran from obtaining nuclear weapons, including a military strike. But he has clashed with Israeli Prime Minister Benjamin Netanyahu, who has suggested Israel could launch its own attack on Iran’s nuclear facilities.

Netanyahu laid out his concerns last month about the “red line” that Iran cannot cross, literally drawing a red line on a cartoon bomb during his speech at the United Nations General Assembly.

Republican presidential nominee Mitt Romney has criticized the Obama administration’s approach to Iran, and warned in a foreign policy address Monday that “Iran today has never been closer to a nuclear weapons capability.”

“For the sake of peace, we must make clear to Iran through actions — not just words — that their nuclear pursuit will not be tolerated,” Romney said.

The ISIS report says the minimum time for producing enough weapons-grade uranium for just one warhead would be two months. It also assumes that Iran is producing the warhead at its Natanz facility — and that production in the underground Fordo plant would take 21 months to produce the necessary amount of uranium.