This book studies the relationshipbetween administrative capacity and a member state’s influence in the EuropeanUnion. More specifically, it studies member states’ ability to exert controlover the European Commission during trade negotiations. But what determinesadministrative capacity and how do member states ensure their preferences aredefended during trade negotiations? A combination of qualitative fieldwork and survey-analysisprovides the answer. Interviews in Belgium, Poland, Estonia and Spain offer aprivileged insight into the functioning of national trade administrations andits effects on their behavior in the Council of Ministers. Through survey data,these findings are further corroborated. The book is aimed at a readershipinterested in EU decision-making, negotiation theory, comparative publicadministration and the international political economy of trade.