This paper examines the US military's impact on climate by analysing the geopolitical ecology of its global logistical supply chains. Our geopolitical ecology framework interrogates the material‐ecological metabolic flows (hydrocarbon‐based fuels, water, sand, concrete) that shape geopolitical and geoeconomic power relations. We argue that to account for the US military as a major climate actor, one must understand the logistical supply chain that makes its acquisition and consumption of hydrocarbon‐based fuels possible. Our paper focuses on the US Defense Logistics Agency – Energy (DLA‐E), a large yet virtually unresearched sub‐agency within the US Department of Defense. The DLA‐E is the primary purchase‐point for hydrocarbon‐based fuels for the US military, as well as a powerful actor in the global oil market. After outlining our geopolitical ecology approach, we detail the scope of the DLA‐E's operations, its supply chain, bureaucratic practices, and the physical infrastructure that facilitates the US military's consumption of hydro‐based carbons on a global scale. We show several “path dependencies” – warfighting paradigms, weapons systems, bureaucratic requirements, and waste – that are put in place by military supply chains and undergird a heavy reliance on carbon‐based fuels by the US military for years to come. The paper, based on comprehensive records of bulk fuel purchases we have gathered from DLA‐E through Freedom of Information Act requests, represents a partial yet robust picture of the geopolitical ecology of American imperialism.