WASHINGTON (AP) — Samantha Power won fame as a human rights advocate and was picked by President Joe Biden to lead the agency that distributes billions of dollars in U.S. aid abroad, including providing more food assistance than anyone else in the world. But since Russia invaded Ukraine, that job includes a new task with a Cold War feel — countering Russia's messaging abroad.

As administrator of the U.S. Agency for International Development, Power is dealing now with a global food crisis, brought on by local conflicts, the pandemic's economic upheaval, and drought and the other extremes typica...