The Conclusion returns to the guiding questions introduced in the Introduction, looking at the way in which the book’s chapters answered them. As such, it identifies recurring themes, experiences, structures, motives, and trends over time. By summarizing the result of the chapters’ research into the interaction between the Secretaries-General and the Security Council, some lessons are identified on the changing calculus of appointments, the conditions and relevance of the international context, the impact of different personalities in that interaction, the changes in agenda and composition of the Council as well as different formats of interaction and different challenges to be met in the realm of peace and security, administration, and reform, as well as concepts and norms. Taken together, they also illustrate the potential and limitations of UN executive action.