Mission that took just one minute to carry out was decades in making, but experts say it could be major strategic error

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The assassination of Iran’s supreme leader, Ayatollah Ali Khamenei, was the culmination of decades of painstaking intelligence gathering by Israeli secret services, with crucial technological resources and manpower provided over the last six months by the CIA and other US intelligence services, which culminated in a single concentrated burst of lethal violence to decapitate the Iranian regime, according to experts, veteran spies and officials in Israel and the US.

Khamenei was killed along with seven “members of the top Iranian security leadership who had gathered at several locations in Tehran” and about a dozen members of his family and close entourage in near-simultaneous strikes within 60 seconds, military officials in Israel said. Forty other senior Iranian leaders also died in the attack.