Michael D. Weiss is one of the foremost investigative journalists covering Russian intelligence and hybrid warfare, and editor of The Insider. Co-author of the New York Times bestseller ISIS: Inside the Army of Terror, he is currently completing a comprehensive history of the GRU, Russia's military intelligence service.

Over the past decade, Weiss has led some of the most consequential reporting on GRU Unit 29155—the covert unit behind bombings, sabotage campaigns, and assassination attempts across Europe and beyond—unmasking spy networks and GRU activities. In 2025, Estonian President Alar Karis awarded him the Order of the Cross of Terra Mariana, the highest honour bestowed on a foreign national, for his work on exposing Russian intelligence operations threatening Estonia and its allies.

A former CNN investigative reporter and director of special investigations at the Free Russia Foundation, he has written for The Atlantic, The Wall Street Journal, Foreign Affairs, and The Guardian, and appears regularly on CNN and MSNBC. He hosts the podcast Foreign Office with Michael Weiss