This paper explores the complex Franco-German relationship in European defence and security, focusing on how their strategic divergences have shaped Europe's defence landscape. It traces the historical evolution of their cooperation from the post-World War II period, marked by key agreements such as the Élysée Treaty and the creation of the Western European Union, which laid the foundations for joint defence initiatives. However, despite these efforts, France and Germany have developed contrasting strategic visions: France champions strategic autonomy, favouring military interventionism and European independence, while Germany prioritises multilateralism, with a stronger reliance on NATO and a cautious approach to military engagements. These differing defence cultures have led to operational challenges, particularly evident in recent crises such as the conflict in Ukraine, where their varied responses have impeded Europe's ability to act cohesively and swiftly. The paper argues that these ongoing strategic differences undermine Europe’s potential to develop a unified defence strategy and highlights the need for deeper Franco-German alignment to ensure a stronger, more coherent European defence posture in the face of evolving security challenges.