Ambassador Tom Shannon at the Tulsa Committee on Foreign Relations

What might be driving Vladimir Putin's aggression toward Ukraine? What might be his motivations -- or his goals, or his aims? As the Russia-Ukraine situation gets more serious, and frankly more alarming, with each passing day, we explore these and related questions with Ambassador Thomas Shannon, who spent nearly 35 years in the U.S. Foreign Service. Ambassador Shannon, who's now a Senior International Policy Advisor with the law firm Arnold & Porter and also a co-chair of that firm's Global Law and Public Policy practice, has moreover served as this country's Under-Secretary of State for Political Affairs (2016–18), its Counselor of the State Department (2013–15), and the United States Ambassador to Brazil (2010–13). He recently gave a talk at the Tulsa Committee on Foreign Relations titled "Diplomacy in a Contested World: How to Keep the Peace and Advance American Prosperity in the 21st Century," and he spoke with us while he was in town.