A week ago, Elon Musk was facing international backlash after endorsing antisemitic content on his social media platform, X. Corporations including Apple Inc. and Walt Disney Co. stopped advertising on the site in protest of hateful and racist commentary. And yet on Monday, Musk was in Israel being welcomed by the nation’s political elite — including Prime Minister Benjamin Netanyahu — to visit the region where the Islamic militant group Hamas murdered 1,200 people on Oct. 7. For all of Musk’s stumbles, world leaders can’t afford to criticize or alienate him for long: The world’s richest person holds the keys...