"My friend, we are totally in line on Syria. We can do great things on Iran. I do not understand what you are doing on Greenland." This message from French President Emmanuel Macron to US President Donald Trump were intended to remain confidential, but Donald Trump published the short message on his Truth Social network on Tuesday night. "He will soon be leaving office," the US president went on to joke about Macron in front of reporters.

Just as Emmanuel Macron is trying to keep the dialogue going, Trump publicly embarrasses the president. Trump regularly imitates Macron's accent in public appearances.

The rift is also likely deepening after a documentary...