There is much more than uranium to a bomb, but IAEA reports surmise that Iran has engaged in extensive studies and experiments with clear military applications - including making uranium metal hemispheres, testing high explosives and multiple detonators (all typical components of a nuclear weapon) and refitting a Shahab-3 missile warhead to fit what looks like a non-conventional weapon. Then, recently, Iran has tested a new missile, which appears to be a modified version of the Shahab-3 with a more accurate delivery. For all we know, the weapon might be ready - it only needs the fissile material to be deployed.

In short, there is little time to talk, even if US negotiators were instructed to do so "under no illusions" and with a clear timeline. Iran appears to be about to cross a critical nuclear threshold - one that would already be the "game changer" of which Obama spoke during his campaign. As French expert Bruno Tertrais recently said, hitherto no country that had reached such an advanced stage in its nuclear programme has decided to forgo nuclear weapons. Why would Iran be different? Dialogue has little time left to work. We hope President-elect Obama realises that.