The very public and acrimonious split between U.S. President Donald Trump and his once-favorite aide, Elon Musk, would be amusing if it were not so terrifying. Their puerile public feud demonstrated just how insecure — even unhinged — the world’s most powerful person and its wealthiest really are.

The collapse came fast. On May 30, Trump was calling Musk “one of the greatest business leaders and innovators the world has ever produced,” and handing him a symbolic golden key to the White House. Though Musk was leaving his post as head of the Department of Government Efficiency, or DOGE as it is better known, he would, according to Trump, continue advising the administration on shrinking the federal budget.

Four days later, Musk was lambasting Trump’s “big, beautiful” spending bill as a “disgusting abomination,” posting a series of screenshots of Trump’s old social-media posts calling for budget discipline and crediting himself for Trump’s second presidency. Trump responded by accusing Musk of turning on the bill because, by eliminating electric-vehicle subsidies, it threatened his personal financial interests.