After decades of globalization and market liberalization, national security concerns increasingly drive market interventions through tools like subsidies, tariffs, and sanctions. These policies center around ‘chokepoints’ within international economic networks, which are sources of power for states controlling them and vulnerabilities for those who depend on them. When do international economic exchanges become chokepoints? Existing theories focus on the structure of the international economic system as well as the characteristics of states, industries, and firms. But this leaves much variation unexplained. For example, one product offered by a particular firm may be a potent chokepoint, while other goods or services by the same producer can be substituted easily. Integrating weaponized interdependence research with microeconomic concepts of market power addresses this gap by identifying the product-level conditions for four types of chokepoints to arise: international network effects, technological advantages, localized raw materials, and monopsonies. Case studies illustrate this analytical framework, advancing our understanding of when states have the capacity to inflict high costs on foreign actors by restricting particular economic exchanges. This framework has important implications for industrial policies aimed at advancing national security and geoeconomic power.