The three-decade mediation effort by the OSCE Minsk Group to resolve the Nagorno-Karabakh conflict ultimately failed due to a convergence of external geopolitical factors and internal conflict-specific dynamics. Geopolitical factors included the complex interests of Russia, the U.S., and France (co-chairs), as well as the rising influence o Türkiye, Iran, China, and Israel. Russia’s, Azerbaijan’s, and Armenia’s shifting interests and the latter’s pivot to the West were detrimental for Nagorno-Karabakh. Meanwhile, Azerbaijan leveraged its energy wealth to build a military advantage, viewing the use of force as its best alternative to a negotiated settlement (BATNA). Western powers prioritized energy routes and countering Iran and Russia over decisive conflict resolution. Internal factors included maximalist demands, the exclusion of Nagorno-Karabakh's leadership from formal talks, and the failure of leaders and mediators to prepare their publics for compromise. Critically, negotiations failed to credibly address the Nagorno-Karabakh Armenians’ fundamental root cause of conflict: existential security. Armenia's overestimation of its position and Prime Minister Pashinyan’s provocative rhetoric and later, unilateral concessions further undermined the negotiation process. The outcome—Azerbaijan’s military victory and the ethnic cleansing of Armenians in 2023—underscores the failure of the rules-based international order, where military might prevailed over the rule of law.