Nigeria, March 24 -- Three weeks ago, as Israeli jets roared through Iranian airspace and American intelligence officers packed themselves into situation rooms across Washington, the mood in Tel Aviv and the White House was almost euphoric. This, they believed, was not going to be another slow-burning Middle East war, a bloody, endless slog with no clear winner. No, this time was supposed to be different. This time, they thought they had found the shortcut.

David Barnea, the head of Mossad, had entered Prime Minister Benjamin Netanyahu's office with a plan so seductive it must have sounded like strategic perfection. Within days of the first missiles landing, he promised, Iran would begin to crack from within. His network of spies and co...