While Obama promises persistence with the Islamic Republic, Iranian authorities are promising persistence of their own, with an outright refusal to discuss their adherence to their NPT safe-guards commitments or the U.N. Security Council Resolutions that resulted from insufficient Iranian cooperation with the IAEA. As Ahmadinejad said this weekend:

As I have declared before, the nuclear train of Iran has neither brakes nor reverse gears. Again today I tell the people of the entire world that the train of progress in Iran has neither brakes nor reverse gear.

There’s nothing wrong with diplomacy, but there comes a time when the Obama administration should recognize its failure. And while Obama promises persistence, his Iran team — Holbrooke, Ross, Burns, Clinton, or whomever has the portfolio on any particular day — should at least define when they recognize it’s not going to work at which point they need to either acknowledge they’re fine with the Islamic Republic becoming nuclear-weapons capable, or outline a broader array of coercive measures to ensure that doesn’t happen.