How are foreign policies developed during times of conflict? This question is often approached by scholars. Here I focus on individual policymakers’ decisions and employ a novel game-theory-inspired analytical framework in foreign policy analysis. The article studies Ukrainian leaders’ decision-making in relations with Russia and the European Union in the first turbulent months of the war in Donbas (April–August 2014). Understanding the beginning of this war holds high relevance in light of the current full-scale Russian invasion of Ukraine. This research is based on analysis of 38 interviews with EU, Ukrainian, and Russian policymakers, and analysis of documents.