The European Union (EU) has taken a geoeconomic turn since 2017 by creating a series of new unilateral instruments designed to preserve European autonomy and adjust to the progressive unravelling of the liberal international economic order. The most controversial of these instruments is the 2023 Anti-Coercion Instrument (ACI), designed to deter third countries from targeting the EU and its member states with economic coercion through measures affecting trade or investment. This article analyses why this new policy instrument was created, traces its institutional genesis and explores its implications by asking whether the ACI represents an intentional attempt to transform the foreign policy issue of coercion into a commercial one. Using process tracing based on interviews and primary and secondary materials, we argue that ‘foreign policy becoming trade policy’ through the ACI was an unintended consequence both of external pressures to institutionalise the trade–security nexus and of the EU's uneven internal competence base.