Introducing the COW Arms Technology Data, 1816–2023: Structure and Applications

This article introduces a new global dataset tracking the adoption of 31 important arms technologies across all states from 1816 to 2023. Covering eight major categories – from small arms and artillery to combat helicopters and ballistic missiles – the dataset provides a comprehensive long-term view of the global evolution and diffusion of arms technology. We describe the conceptual foundations and coding procedures, as well as transformations of the final data relevant for scholars of international relations and comparative politics. We demonstrate the relevance of the data through three empirical applications: we show that arms technologies spread in ways consistent with the logic of the security dilemma; that technological superiority helps explain which states win wars, and that advanced arms help autocrats stay in power. These findings highlight the central role of arms technology in shaping both the global distribution of power and the durability of autocratic regimes.