FOR SOME time, there has been a strenuous effort to prepare the way for a pre-emptive strike against Iran, either by the U.S. or by Israel with American acquiesence. Those promoting such a military assault are the same people who promoted war in Iraq by telling us that Saddam Hussain had weapons of mass destruction, was tied to al-Qaeda, and played a role in the Sept. 11 terrorist attacks. Now, we are told that Iran represents an “existential” threat and that any nuclear program it pursues—however far from achieving a single nuclear weapon it may be—must be eliminated.