Theo manages grants on nuclear issues. His portfolio encompasses domestic and international policy, technology and innovation, as well as tracking broad geopolitical trends, including how nuclear and climate issues converge and interact with each other. Before joining MacArthur, he was a program staff member of the International Peace and Security Program at Carnegie Corporation of New York. Previously Theo was a consultant and speechwriter in the External Relations section of the Comprehensive Nuclear-Test-Ban Treaty Organization, a United Nations-family organization based in Vienna, Austria.
Theo has a Master of Arts in International Policy Studies from the Middlebury Institute of International Studies at Monterey and a Bachelor of Arts in History from the University of California, Berkeley, where he graduated Phi Beta Kappa.
Theo is an Internal Advisor to MacArthur's Climate Solutions program, and he serves on the Steering Committee of the Peace and Security Funders Group.