While we don’t know the substance of what was discussed, Musk’s presence is a concerning preview of Trump’s often reckless approach to diplomacy — as well as his disregard for the line between private interests and public policy. There are a lot of reasons why Musk should be the last person hopping on that call.

By helping bankroll Donald Trump’s campaign, Elon Musk has gained unprecedented power. His new role as the arbiter of government efficiency opens up glaring conflicts of interest, allowing him to potentially reap huge rewards for his companies while disrupting industries and sidelining rivals.

Elon Musk has been at Trump’s side at Mar a Lago and in Washington since the election. How great is his influence? And could he wear out his welcome?