Hopefully what we can do is to persuade the Iranians that it would be really stupid idea for them to build just one nuclear weapon, because if they were to explode just that one nuclear weapon, they would face tremendous international isolation and what Secretary of State Hillary Clinton referred to as “crippling sanctions”—and, indeed, quite possibly more. If Iran clearly only had one nuclear weapon and exploded it, then the United States government would be seriously debating whether to take pre-emptive military action, and a number of governments around the world, including many Arab governments, would be urging us to do it.
Hopefully what we can continue to do through combined efforts in the international community is to persuade the Iranians to go slow on this thing, and to say to them, okay, you are piling up great quantities of low-enriched uranium, but don't even think about doing more than that. Let us remember that most of the countries who started weapons programs abandoned them. My favourite example of this is the Swiss, who twice voted in public referenda in favour of building nuclear weapons and then in favour of testing the nuclear weapon inside Switzerland. It was only because of an accident in the tunnel they were building for this that they decided to change their mind. But lots of countries that have gone down this road even farther than Iran has in the end have backed off.