Whether Iran is irrational enough actually to deploy a nuclear weapon is a question we wouldn’t be able to answer until it is too late (if yes) or wouldn’t ever be able to definitively answer (if no). But it’s also, according to Middle East columnist Lee Smith today in Tablet Magazine, irrelevant: what matters is whether a nuclear-armed Iran would gain increased leverage to act in ways that counter U.S. and Israeli interests. Here, we already know the answer.