Amid continued British-US airstrikes in Yemen, the Ansarullah movement—better known as the Houthis—has significantly intensified its intimidation tactics in the country. Since May 31, the group has arbitrarily arrested UN staff as well as employees of international and national organizations operating in Sana’a. Moreover, in June, the Houthis declared that they had detained an “American-Israeli” spy cell “directly linked to the CIA”—accusing those arrested of engaging in “espionage and sabotage in both official and unofficial institutions.” They subsequently broadcasted what appeared to be forced confessions from ten former employees of the US embassy, which closed its operations in 2015.

In response, the US Mission to the UN indicated that a total of “50 Yemeni employees of UN agencies, Member State diplomatic...