A common reaction to that notorious Trump/Zelensky press conference is
“we haven’t seen anything like this before”. Seen is the key word.
Bust-ups and walk-outs do occur in diplomacy, the difference is that
Donald Trump does in the open what is meant to be conducted in private. An example: in 2022, NBC reported that
Joe Biden had spoken to Zelensky by phone about a $1 billion aid package, and
when Zelensky began asking for more, the US president “lost his temper” and told him to be more grateful.
So, yes, America argues with its friends. Worse than that: it has a record of abandoning them. I’m struck by the parallel between Ukraine and South Vietnam, two regimes encouraged by the US to fight an invader – at huge cost in money and lives – only for Washington to cut and run.