The aim of the project is the development of game theoretical models and the empirical study of their explanatory power on European decision making. More precisely, we will focus on two-level games which provide explanations for strategic threats and promises in European bargains. We will first scrutinize whether both bargaining strategies are theoretically equivalent, second we will assess central assumptions of two-level games by case study analyses, and third we will use these non-cooperative models within a international research collaboration which analyses the explanatory power of competing approaches on European decision making.