Near the conclusion of Tuesday night’s second presidential “town-hall” style debate, a questioner from the audience asked each candidate what he would do if Iran attacked Israel. Both candidates gave somewhat vague replies, focusing on the traditionally close relationship between the United States and Israel. In any event, if Iran ever attacks Israel, other than through its Lebanon-based surrogate Hezbollah, it will be with nuclear-tipped missiles, in which case Israel will be obliterated before the United States can respond. The more pertinent question for the candidates is, “What will you do if and when Israel carries out a preemptive attack...