Why do some countries cooperate in international negotiations while others do not? There is consensus in the literature that democracies are cooperative and that coun- tries that trade intensively with one another also cooperate more. In order to examine the impact of regime type and trade relationship on cooperation between countries, we investigate cooperation in the World Trade Organization (WTO). We explore how the interaction between these two factors can help us better explain international coopera- tion. We show that democracies are more cooperative with one another and with various authoritarian regimes but only at high levels of trade. Our findings thus qualify existing knowledge by showing that democracies are not necessarily more cooperative by nature, but their cooperation is driven by increased trade volumes. Our analysis is based on 1567 documents submitted by individuals or groups of WTO members between 2000 and 2012, roughly corresponding to the Doha rounds negotiations. The time frame around the Doha Round offers a good opportunity to analyze WTO negotiations. It allows us to observe the challenges of multilateral trade liberalization at a particularly dynamic time. It had an ambitious agenda, a broader set of developing countries were involved, and complex bargaining dynamics emerged around issues like agriculture, industrial tariffs, and de- velopment concerns.We model the amount of cooperation observed between dyads using hurdle models and show that dyads with at least one democratic member which exhibit higher trade flows are more cooperative. These two effects reinforce each other. Our paper thus contributes to a better understanding of international cooperation in multilateral settings.