Observers watched the 2020 Nagorno-Karabakh War closely, searching for indicators of the character of warfare on tomorrow's battlefields. The lessons extracted have covered advanced technology and unmanned platforms, proxy dynamics, the ongoing relevance of armor, and more. But some of the most important lessons have received much less attention. They center around the increasingly unavoidable importance of combat in cities and are drawn principally from the battle for the city of Shusha—a fight that arguably decided the outcome of the war. Listen as John Spencer, chair of urban warfare studies at MWI, explains why.