The new Foreign Malign Influence Center oversees efforts that span U.S. military, law enforcement, intelligence, and diplomatic agencies. WITHIN THE FEDERAL government, offices dedicated to fighting foreign disinformation are springing up like daisies, from the Pentagon’s new Influence and Perception Management Office to at least four organizations inside the Department of Homeland Security alone, as well as ones inside the FBI and State Department. To oversee the growing efforts — which arose in response to concerns about the impact of Russian meddling in the 2016 election but have now expanded — the director of national intelligence has created a new...