This chapter examines to what extent Europe’s governments and defence contractors cooperate to provide European Armed Forces with military capabilities. Defence industrial cooperation has evolved as almost the default policy option for European powers to develop large military platforms. Yet, there is no uniform trend, but large variation across countries (for example, France versus Germany), across sectors (land versus air versus sea), and with regards to the sources of cooperation (for example, government induced versus investment driven). The chapter shows that, while the major powers dominate defence industrial cooperation both at the government and at the corporate level, the lesser powers and smaller defence firms follow the trend and participate in the supply chains of large weaponry. Finally, the chapter addresses the question whether cooperation or competition represents the most promising strategy towards a capable European Defence Technological and Industrial Base.