What if Iran doesn't actually plan to use a nuclear weapon? What if Iran wants, as various of its officials have said over the years, to prevent being toppled the way Saddam Hussein was, or Moammar Gaddafi or Hosni Mubarak? To prevent a 20-year U.S.-led invasion like that of Afghanistan? Nuclear-armed North Korea, not to mention Russia and China, have received far more forbearance from the U.S. than the leaders of Iraq, Libya, and Egypt, or the Afghan people. Yes, all things considered, its better to be a nuclear-capable Iran than not. Iran might be willing to accept delays in...