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.

President-elect Trump has announced Elon Musk will lead a new cost-cutting agency called the Department of Government Efficiency. Democrats have raised “serious concern” over Musk’s companies having major contracts with the federal government.