Precisely. Does anyone think that the Iranians don't understand the US position on their nuclear enrichment program? So what would be point to talking to them? To offer to enrich uranium for them? The Russians have already done that. To sign a "non-aggression" treaty with them, so that they'll have an incentive not to produce nukes? When did we ever seriously threaten them (prior to their attempts to produce nukes)?
There's only one subject the Iranians want to talk about, and that's how they can keep their "peaceful" nuke program going (like El Baradei suggested, so that the mullahs don't lose face), with a very loose inspection regime that they could cheat on if they were so disposed (which of course they're not, take their word for it). Naturally, they'll be delighted to offer President Bush a Clintonesque photo op, where he can shake hands with Ahmadinejad, and sign a "treaty" that "guarantees" nuclear peace in our time.