WASHINGTON—U.S. Secretary of State Antony Blinken announced on Friday that he will revoke—effective Feb. 16—designations of Yemen’s Houthi movement as a foreign terrorist organization and a specially designated global terrorist group. The decision, reversing the former Trump administration’s blacklisting of the Houthis, is part of a policy shift by U.S. President Joe Biden aimed at easing the world’s worst humanitarian crisis and intensifying diplomacy to end Yemen’s grueling civil war. “This decision is a recognition of the dire humanitarian situation in Yemen,” Blinken said in a statement. The war pits the Iranian-aligned Houthi movement against Yemen’s internationally recognized government backed by a Saudi-led military coalition. The Biden administration, other governments, the United Nations, and aid organizations shared fears that the sanctions imposed on the Houthis under the designations could strangle food deliveries just as the threat of major famine is rising. Blinken, however, appeared to signal limits to U.S. tolerance …