The challenge came from the sky. With a swarm of twenty drones, probably combined with the launch of cruise missiles. The US seems convinced of Iran's direct role as some observers chase less clear tracks. On Sunday evening, Washington released satellite photos of affected Saudi plants, images that raised other questions about systems used in the attack on oil sites. Tiles of a dossier examined by the White House preparing its answer. Trump waits for more information and then decides: he has not ruled out retaliation.