International tax competition undermines states’ capacity for redistributive taxation. It is thus problematic from the point of view of both cosmopolitan and internationalist theories of justice. This article examines the proposal of a fiscal policy constraint that prohibits tax policies if they are strategically motivated and harmful to effective fiscal self-determination internationally. I argue that we should opt for a more robust, preference-independent mechanism to prevent harmful tax competition instead. States should, as a matter of justice, accept global minimum tax (...) rates on mobile tax bases. (shrink)