...Even diplomats who say the Houthis do not qualify as a terrorist organization, and objected to the designation, recognize that “they are certainly an odious group,” said Gerald M. Feierstein, the ambassador to Yemen during the Obama administration.

“So how do you remove the F.T.O. designation without suggesting that you sympathize with them or hold them blameless for the catastrophe in Yemen?” said Mr. Feierstein, now with the Middle East Institute in Washington. “It won’t be easy.”