This thesis explores the motivations behind Bolivia’s refusal to sell natural gas to neighboring country Chile. It focuses on the backlash surrounding the 2003 Gas Wars and the non-cooperation that followed. Specifically, it analyzes two cases—in the 2000s and 1950s—when Bolivia successfully cooperated with Chile in the petroleum sector. While many scholars argue that rivalry has motivated Bolivia's decision to avoid cooperating with Chile, this thesis challenges that position. This thesis hypothesizes that three factors, when all present, contribute to Bolivia’s decision not to cooperate with Chile in the natural gas sector. The first factor that influences this decision is disillusionment with the governing administration’s economic policy. This disillusionment leads to both the administration losing credibility and the populace approaching its policy with distrust. If this factor is present, it creates the opportunity for oppositional political elites to leverage the other two factors, resource nationalism and rivalry with Chile—Bolivia’s most politically charged and compelling narratives—to fully impede cooperation. This thesis tests this theory on both case studies.