The chapter explains executive dualism and presidential activism. It focuses on conflicts within the executive and the circumstances that trigger or influence such conflicts. It also looks at the issue of informal presidential power, which repeatedly plays a key role in the case of presidents and significantly affects their position in general and in executive dualism. Particular attention is paid to executive dualism in foreign policy, a major theme throughout the book. We present a typology of relations within the executive and presidential activism and later apply the resulting model to Central European presidents during the analysed wartime conflicts.