Let’s define this in simple statements.
A. Iran is a supporter of terrorism, and they have ambitions to build nuclear weapons. They hate us, frequently chanting “death to America.”
B. U.S. President Donald Trump is putting enormous economic pressure on them to stop supporting terrorism and to give up their nuclear ambitions.
C. French Prime Minister Emmanuel Macron would like for the U.S. to relieve some pressure on Iran and return the U.S. to the Iran deal, which was negotiated by Obama and which not only was ineffective to start with, it was also violated by the Iranians.
D. Iran has made no actions nor given any sign that they will stop supporting terrorism or give up their nuclear ambitions.
E. Trump has stated that he will speak with them any time, but he will not give any concessions nor relieve any pressure until Iran agrees to stop supporting terrorism and gives up its nuclear ambitions.
F. Iran has declined to meet. In fact, in recent months they have been belligerent and have committed acts that could easily have led to war.
G. Macron invited the Iranian foreign minister Mohammed Javad Zarif to the G7 Summit where Trump is in attendance.
Analysis: What did Macron promise to the Zarif? There was no reason for him to show up unless he thought something good would come from it. Did Macron tell him that Trump might be softening or perhaps that together they might get Trump to concede something?
Does Macron not agree that Iran supports terrorism or that Iran wants to build nuclear weapons?
Does Macron want Trump to concede that Iran can continue to support terrorism, or that Iran can go ahead and build nuclear weapons?
Clearly, Macron was hoping to have a spontaneous meeting between Trump and Zarif. But Iran has not only been stubborn in its resolve to get nuclear weapons, it has been belligerent to the point of inciting war. For Trump to meet under these circumstances would appear exceedingly weak, in American terms, and weak and vulnerable in most Middle Eastern cultures.
As Nikki Haley said, this was exceedingly disrespectful to Trump, to attempt to manipulate the circumstances, which would put Trump at such a disadvantage.
This was foolish and awkward, a mistake that an experienced diplomat and negotiator would not have made.