The Armenian–Azerbaijani conflict for control of the mountainous territory of Nagorny Karabakh is the longest-running dispute in post-Soviet Eurasia. Laurence Broers shows how more than 20 years of dynamic territorial politics, shifting power relations, international diffusion and unsuccessful mediation efforts have contributed to the resilience of this stubbornly unresolved dispute. Looking beyond tabloid tropes of ‘frozen conflict’ or ‘Russian land-grab’, Broers unpacks the unresolved territorial issues of the 1990s and the strategic rivalry that has built up around them since.