Jamie Dimon, the billionaire head of the U.S.’ biggest bank, lauded Tesla CEO Elon Musk, the richest man on the planet and a key part of President Donald Trump’s administration, this week, putting an end to years of head-butting between the billionaires’ companies as Dimon becomes the latest billionaire warming to Musk or Trump.

The JPMorgan Chase chief executive, who had warned of the negative effect of tariffs, said they could be justified for national security reasons.