Today, Europeans are wondering about the United States’s political future while Americans worry that Europe remains politically and materially unprepared to shoulder its own security. On both sides of the Atlantic, the rise and popularity of revisionist movements threaten to flip the traditional relationship on its head. All the while, the United States and Europe must deal with additional challenges, such as economic and technological competition with China. The Carnegie Endowment’s Europe program in Washington, D.C. examines key issues defining the next chapter of transatlantic cooperation.