This study tests the ability of James D. Fearon's Bargaining Range theory in explaining the different outcomes of negotiations during the Kosovo War; the failed Rambouillet negotiations and the successful Kumanovo Agreement. Through a qualitative, theory-testing case study, the research investigates how power dynamics, information and trust, and issue indivisibility shaped the two negotiation's outcome. Findings suggest that the Rambouillet negotiations failed primarily due to a Serbian power advantage, distrust between parties, and the presence of indivisible issues. NATO’s military intervention reversed the power dynamics before the Kumanovo Agreement, increasing transparency and forcing compromise, despite the persistence of core indivisible issues. The results support Fearon’s theory, emphasizing that power dynamics and credible commitments can expand the bargaining range. This study contributes to the empirical validation of rationalist explanations for war and highlights the role of international actors in shaping negotiation dynamics. It serves as a useful tool for military personnel to understand the complexity and scale of a war they may encounter and thereby encourage greater understanding of purpose and ability on a strategic and operational level.