The most common theory about why President Obama seems reluctant to negotiate seriously with Iran is that a presidential campaign is no time for serious negotiations. If Obama makes concessions--and concessions, after all, are part of serious negotiation--he'll be accused of appeasement by Mitt Romney and a flock of right-wing hawks.
Flynt Leverett and Hillary Mann Leverett are now advancing a second theory: the administration's plan isn't just to get through the election without conducting serious negotiations--after which, according to the standard theory, talks with Iran can begin in earnest; no, the plan is to get through eternity without conducting serious negotiations:
In reality, [Obama's] administration is "buying time" for a more pernicious agenda: time for covert action to sabotage Tehran's nuclear program; time for sanctions to set the stage for regime change in Iran; and time for the United States, its European and Sunni Arab partners, and Turkey to weaken the Islamic Republic by overthrowing the Assad government in Syria.
The Leveretts, who served in the Bush administration, are Iran experts with good connections to people in the Iranian government. Indeed, they've drawn fire from neoconservatives who claim their proximity to Iranian officials has left them too sympathetic to the regime.
My own view is that there is currently a dangerous shortage of people trying to help us understand how the world looks from Iran's point of view (a kind of understanding that typically abets successful negotiation, even if that's a moot point for now). And in this case I think the Leveretts have performed a particularly valuable service, because, whether or not the Obama administration really is angling for regime change, you can see, after reading their article, how the Iranian regime would think that's the administration's goal.
And the more the Iranians think that, the more they'll want nuclear weapons. After all, look what's happened to the regimes we wanted to change that didn't have nuclear weapons--Qaddafi's and Saddam Hussein's. Compare that with the fate of the regime we'd like to change that does have nuclear weapons--the North Korean regime, which is still standing, in all its glorious absurdity.
So regardless of the correct explanation for our current diplomatic inertia (and I'm personally still drawn to the standard theory), this inertia, combined with ever more draconian sanctions, may well be having a perverse effect: strengthening elements within the Iranian government that favor building a nuclear bomb. And so too with the various illegal things America and/or Israel have done to try to slow Iran's nuclear program: murder, sabotage, etc. The greater the sense of siege, the stronger the argument within Iran for building a bomb.
So as we try to retard Iran's nuclear program--and as we stall on the negotiating front, while applying more and more economic pressure--we may be, in effect, converting the program from a civilian to a military one. Or, more precisely: we may be taking a nuclear program whose ultimate character is undetermined and making it more and more likely that this character will be military. And that seems kind of stupid.