Excerpted from JPost:
French president Valery Giscard d’Estaing later explained to me that in 1979 he, Helmut Schmidt of Germany and James Callahan of Great Britain met with Carter on the island of Guadalupe. Carter informed this group that the US was going to support Khomeini instead of the shah. The French leader said he realized the US was trading its strongest Persian Gulf ally in favor of a terrorist Muslim cleric.
D’Estaing said he knew that without US support the shah’s regime would be lost, and defined Jimmy Carter as a “bastard of conscience, a moralist who treated with total lightness the abandonment an ally that we had supported in exchange for a cleric Carter thought would be better for human rights.”
