Based on a critical reading of Trotsky’s celebrated The War Correspondence, this article addresses the complex links between war and memory. It offers a detailed analysis of the correspondence, arguing for its present relevance in several aspects, beyond its polemical brilliance: firstly, its detailed information and personal evaluation of the socialist movement in the Balkans; secondly, its testimonies of wounded officers, soldiers, and prisoners of war, reproduced in extenso, in combination with interviews with politicians, serve as a rarely preserved primary source. The article considers The War Correspondence’s formative significance on Trotsky himself by juxtaposing it with his later autobiography and political activities, and follows his evolution from a passionate defender of liberalism to one of its most bitter opponents. It finally utilises the distinction between lieux and milieu de mémoire to comment on the present memory of wars and the centenary of the Balkan Wars.