TEL AVIV—The Israeli prime minister appears asleep in bed, while warnings of a Hamas attack flash across the screen. Senior judges are shown being dragged through the streets after protesting the government. The mayor of New York holds a party to celebrate the downfall of longtime Israeli leader Benjamin Netanyahu. In the corner of each piece of footage a small message carries the label “AI” and in Hebrew reads: “The content was produced by digital means and wasn’t actually documented.” Such footage has been posted online by the country’s most senior lawmakers, as well as the prime minister. This is…