The pessimism is understandable. In the wake of President Trump's withdrawal from the Iran nuclear deal, the only people who seem happy are those who have long advocated for regime change and pre-emptive war, while those who have learned the lessons of Iraq are apoplectic or depressed. If the Iranians restart their nuclear program in response to the American pullout, and America or its regional allies respond with military force, the result would be an escalation of the many-sided Middle East conflict, with unpredictable consequences, few of them plausibly good. But it's worth examining the more optimistic case. Not the notion that American pressure will suddenly bring about a better deal with Iran, where the regime abjures terrorism, shuts down its missile programs, opens its prisons, and allows fully free elections. After the abject failure of our confrontational policies in Cuba, North Korea, and elsewhere, it's very hard to credit anyone's continued belief that adversaries can simply be bullied into submission.