It's easy to castigate Iran's President as a lunatic, albeit a genocidal one with a nuclear weapon and cutting edge ballistic missiles. With his Holocaust denial conference, however, we're beginning to suspect that there's very much something to his suggestion last month that there is a strategy behind his anti-Israel rhetoric. Don't make the mistake of thinking that he's simply stark raving mad - what he is doing is precisely introducing the most vicious anti-Semitic lies and the most genocidal of intentions into the spectrum of public discourse. The market-place of ideas aside, it quite simply matters what is being discussed and what isn't. Ideas can be defeated, but discourse leaves its mark. Ahmadinejad will be castigated, but someone will ask why he's being castigated for expressing ideas. And then someone will protest that he's being shouted down. And then somebody will give voice to the suspicion that maybe there is something unseemly behind the vehement opposition to him. It's the classic problem with answering conspiracy theories - you don't want to legitimate them with reasoned opposition, but refusing to address them allows the conspiracy theorists to insist that their opponents are 'afraid to debate them'. So no one of any public respectability will show up at Ahmadinejad's Holocaust denial fest - but everyone who does show up will insist that the reason why only one side is represented is because the other side is lying.