On April 8, according to the Washington Post, this past weekend, when Elon Musk made a series of posts on social media criticizing the tough tariff plan promoted by one of President Trump's key White House advisers, he actually went beyond the official and made a direct appeal to Trump himself. Mr. Musk's intervention has yet to bear fruit, according to two people familiar with the matter, who spoke on the condition of anonymity because of private conversations, but Mr. Trump has also said he is open to negotiations over parts of the policy. At the same time, Mr. Musk posted a video of the late conservative economist Milton Friedman on the X platform, in which Mr. Friedman highlighted the benefits of international trade co-operation, calling it "the non-adding personal touch of price", and used an ordinary wooden pencil as an example to analyze the global sources of its various raw materials.