As the world seeks ways to retaliate against U.S. tariffs, so-called "first buddy" Elon Musk appears to be high on the list of targets. Why it matters: Targeted retaliation is designed to give supporters of Donald Trump an incentive to try to persuade him to deescalate any trade war.

President Trump has tasked Elon Musk with an enormous job of searching the federal government and rooting out inefficiencies and waste. But Musk’s initial, often chaotic, infiltration of various departments has set off alarm bells.