(Too horrible to contemplate... I'm sorry to even bring this up.)
Suppose that Israel or America turns out to be afraid, or too stupid, or too weak to do what it takes to prevent Ahmadinejad from developing his atomic bombs. And (G-d help me for even uttering these words) suppose Iran somehow, say in 10 years, gets a nuclear bomb (or bombs) into Israel and sets it off. Then what? (I actually live with this fear every day.)