Joseph Cirincione -- Five Myths About Iran's Nuclear Program

Attacking Iran would not end the problem; it could start a third U.S. war in the region.

3. We can cripple Iran with sanctions.

Sanctions rarely, if ever, work on their own. There is no silver bullet that can coerce Iran into compliance or collapse.

Some mix of sanctions -- whether restricting travel, making it harder for Iranian banks to do business, further limiting foreign investment or even denying Iranian citizens basic needs, such as gas -- may be necessary if Tehran does not restrain its nuclear program or live up to its pledges. But the key is to couple such pressure with a face-saving way out for the Iranian leadership. As the 2007 National Intelligence Estimate on Iran put it, a sanctions strategy must feature "opportunities for Iran to achieve its security, prestige, and goals for regional influence in other ways." These could include Iran's inclusion in regional security talks, the suspension of sanctions and a secure supply of reactor fuel, leading up to normalized relations with the West.

No nation has ever been forced to give up nuclear programs, but many have been persuaded to do so, including Brazil, Argentina, Ukraine, Belarus, Kazakhstan, South Africa, Iraq and, most recently, Libya.

4. A new government in Iran would abandon the nuclear program.

Some believe that an irrational, apocalyptic government now rules Iran and that regime change is the only solution. But there is broad support across Iran's political spectrum for the right to peaceful uses of nuclear energy.

Recall that the country's nuclear program began with the shah, a U.S. ally who had plans to build 20 nuclear reactors, similar to the plans the mullahs promote today. The shah also started covert work on nuclear weapons. The U.S. government knew about this research but looked the other way, going as far as selling Iran its first nuclear reactor.

Even with a reformist government, it is unlikely that Iran would quickly end its nuclear program. But its leaders might be persuaded to limit the program's nuclear weapons capabilities. "Tehran's decisions," according to the 2007 National Intelligence Estimate, "are guided by a cost-benefit approach rather than a rush to a weapon irrespective of the political, economic, and military costs."