Does world politics affect the adoption of new technology? States overwhelmingly rely on technology invented abroad, and their differential intensity of technology use accounts for much of their differences in economic development. Much of the literature on technology adoption focuses on domestic conditions. We argue that the structure of the international system is critical. It affects the level of competition among states which in turn affects leaders’ willingness to enact policies that speed technology adoption. Countries adopt new technology as they seek to avoid vulnerability to attack or coercion by other countries. We examine this systematically by considering states’ adoption of technology over the past 200 years. We find that countries adopted new technologies faster when the international system was less concentrated, that systemic change Granger-caused technology adoption, and that policies to promote technology adoption were related to concerns about rising international competition. A competitive international system is an important incentive for technological change, and may underlie global “technology waves”.