Screw ‘em.
They won’t accept, or be placated by, any explanation.
Move on.
Thousands upon thousands of American war dead to save their sorry wine soaked cheese fattened asses in three wars (Remember Vietnam was also French Indo-China) and they have DeGaulle /snicker to insult our president and thereby all of us by remarks like that. I say screw them and let them chill in their own vichyssoise.