The EU is adopting a set of unilateral trade-related measures that are designed to produce specific environmental effects. Increasing recourse to environmental leverage triggers an array of questions surrounding the treatment of ‘differently situated’ (including developing and least developed) countries. This article critically examines the extent to which the Chapeau (introductory clause) of Article XX GATT requires regulating Members to differentiate the treatment of ‘differently situated’ countries where the same relevant conditions prevail, or take their different prevailing conditions into account at the regulatory design or regulatory implementation stage. It finds that the dispute settlement organs’ narrow interpretative approach cannot do justice to the claims of ‘differently situated’ countries, but has several beneficial implications in environmental protection terms. As the climate crisis spirals out of control, the environmental cost of differentiation has become too high. Regulating Members should rather combine stringent unilateral standards with truly ambitious enabling and capacity-building strategies.