This chapter does not advocate for one particular brand of realism as the supreme analytical tool.Instead, it presents a synthesis of theories across International Relations to explore the various factors that shape how states and nonstate actors approach peace.No one theory is “the best” at explaining peacekeeping and peacemaking.Rather, each theory provides a piece of the puzzle that explains peace as a dependent variable.This chapter begins by defining realism and integrating the various subtheories of realism to provide a framework to explain when actors choose cooperation over conflict.It frames the discussion in the context of realist strategies for maintaining peace and resolving conflicts. The synergistic cross-paradigmatic approach I propose explains how the various theories shape actor behavior, within the structure provided by realism. The chapter concludes by highlighting the outstanding shortfalls that remain in any peacebuilding approach