The European Union and international outcomes

Analysts of the European Union (EU) and international bargaining have gener ally failed to appreciate how the shift within the EU from unanimity to qua lified majority voting has affected European bargaining positions and inter national outcomes. I analyze the international effects of changes in EU dec ision-making rules with a simple spatial model and assess the utility of th e model in two cases that span the entry into force of the Maastricht Treat y. The EU can decisively shape international outcomes by concentrating the weight of its fifteen member states on a single substantive position and re ndering that position critical to any internationally negotiated agreement. The findings generalize to numerous areas of EU external relations and sug gest that analysts should attend specifically to the EU and more generally to domestic and regional institutional factors in explaining international bargaining outcomes.