Which form of capitalist governance best fosters peace, prosperity, social cohesion, and environmental protection? I argue that making sense of this complexity calls for revisiting the three different principles of capitalist governance: liberty (freeing the market to unleash growth), solidarity (reining in the free market to protect the weak and the environment), and community (safeguarding the group through protectionism and military might). I contend that studying the European Union helps provide insight into how a compromise between liberty, solidarity, and community capitalisms is struck, as the Union is in a constant process of negotiation among bickering members. Dealing with community capitalism, in particular with protectionism and nationalism, has been the most pressing challenge for Europe in the past, not just today. This book will focus on the interaction between capitalism and European integration between 1945 and 2025, drawing on studies from areas of scholarship that rarely enter into dialogue with one other (history, political science, comparative political economy, international relations), as well as through new archival research.