Militaries around the world are a major source of carbon emissions, yet very little is known about their carbon footprint. Reliable data around military resource use and environmental damage is highly variable. Researchers are dependent upon military transparency, the context of military operations, and broader emissions reporting. While studies are beginning to emerge on global militaries and their carbon footprints, less work has focused on wartime emissions. We examine one sliver of the hidden carbon emissions of late-modern warfare by focusing on the use of concrete “blast walls” by US forces in Baghdad over a five-year period (2003–2008). This study uses a Life Cycle Assessment (LCA) to study one of the world's largest military carbon footprints of concrete, an infrastructural weapon in late-modern urban counterinsurgencies. Moving beyond dominant discourses on climate-security and “greening”, we present one of the first studies to expose direct and indirect military emissions resulting from combat.