> Intelligence officials say there is little doubt that Israel was behind the killing — it had all the hallmarks of a precisely timed operation by Mossad, the country’s spy agency. And the Israelis have done nothing to dispel that view. Prime Minister Benjamin Netanyahu has long identified Iran as an existential threat, and named the assassinated scientist, Mohsen Fakhrizadeh, as national enemy No. 1, capable of building a weapon that could threaten a country of eight million in a single blast.