I think you have made an excellent point.
Remember, back in the 1930s, Nazi Germany wanted to solidify its position as the leader of Aryan Europe. Its goal was to try to get Austria to join, and to try to get even Great Britain and the Scandinavian and other Aryan countries, and Italy, to join with it. It used incitement to genocide as one way of bringing together that coalition. Simply because there were political ends, that doesn't mean that the means used—incitement to genocide—are in any way protected.
I do think that the greatest fears and dangers posed by a nuclear Iran are not necessarily directed at Israel alone. Israel does have the military capacity on its own, and with the help of allies, to at least respond—hopefully it will never come to that--and if necessary to act preventively. And hopefully it will never come to that as well. But the great threat is to the other countries. Imagine if Iraq had been allowed to develop nuclear weapons and then went into Kuwait. They'd still be there today, because you cannot end a country's aggression if it has nuclear weapons that it's capable of using.
The other great threat is that it will begin an arms race. Saudi Arabia has the capacity to buy nuclear weapons. Probably Egypt and Jordan, and maybe even some of the Emirates, would feel so vulnerable and exposed, because remember that Ahmadinejad, in his speech at the UN in Geneva last week, directed his attention not only against Israel but against “all liberal democracies in the world”—Canada, the United States, Western Europe. His goal is to end democracy. He thinks democracy is a dinosaur and would substitute a kind of religious fundamentalism, backed by nuclear weapons.
I agree with you completely that Ahmadinejad is the symbol and the symptom. It's different from Nazi Germany, in the sense that Adolf Hitler was the supreme leader and was the chancellor and was the visible manifestation and the führer in every sense of the word. Iran is more complicated. There will be an election in Iran coming up in June, and we don't know the outcome of the election. But in a society based on overt acts in what you say and what you do, Ahmadinejad has presented himself as the person issuing these directions and instructions, and it would be appropriate to him to be the first person prosecuted.