External trade policy is among national and European technocrats’ most carefully guarded portfolios, routinely resisting every attempt to transfer powers in concluding international trade agreements to the European Parliament. The Lisbon Treaty, however, opened a door to the European Parliament on external trade, granting it legislative powers over the EU’s trade policy and the right to veto international trade agreements. In her article “The impact of norms on political decision-making: how to account for the European Parliament’s empowerment in EU external trade policy” published in the Journal of European Public Policy, Guri Rosén seizes on this puzzle and shows how the debate surrounding the empowerment of the European Parliament in external trade “became embedded in the general discussion about its legislative role in a more democratic EU.” Guri argues that during negotiations on the Lisbon Treaty, uncertainty and disagreement regarding the principles guiding reform placed a higher demand on actors to explain their positions. This environment favoured proponents of empowering the European Parliament in trade policy, and allowed the European Commission and the European Parliament to convince Member State governments “that extending the EP’s trade powers was reasonable because there were no valid arguments for exempting trade from the general rule of linking QMV and codecision.”