WASHINGTON—This is exactly what President Trump and his advisers were trying to avoid. Just six days ago, senior Trump aides swallowed their irritation with Elon Musk and planned a chummy Oval Office send-off for him.

Private tensions between the world’s most powerful man and the world’s richest spilled out into a public war on Thursday, ending the alliance between President Donald Trump and Elon Musk in the most dramatic way possible.

President Donald Trump has issued a new warning to Elon Musk just days after their one-year political partnership blew up in spectacular fashion. Trump said the billionaire entrepreneur who left his administration late last month after directing the Department of Government Efficiency (DOGE) had