The Eastern Mediterranean is the Achilles heel of the European Union (EU) and NATO. The political cohesion of the Western Alliance, Europe’s autonomy on matters of security policy, and the EU’s energy resilience are all put to the test in the region. This study focuses on the conflict between Greece and Turkey in the Aegean Sea, which highlights the complexity of the security policy challenges facing the region. It identifies developments in the field of security policy and derives possible recommendations for action.