This chapter analyses the evolving landscape of European Union security and defence, focusing on Bulgaria’s strategic role as a frontline state in the Black Sea region. It argues that while NATO remains the cornerstone of Bulgaria’s security framework, there is a gradual yet notable shift towards supporting a stronger European defence dimension. This shift is driven both by changing threat perceptions - particularly following Russia’s invasion of Ukraine - and by increasing public and political recognition of the need for enhanced European strategic autonomy. The chapter highlights Bulgaria’s dual-track approach: on the one hand, persistent structural challenges; on the other, tangible progress in defence investment, capability development, and participation in EU and NATO initiatives. Public opinion emerges as a critical factor shaping Bulgaria’s security policy. Survey data reveal a complex and often contradictory societal outlook, that underscores the difficulty of building a coherent national consensus, even as threat perceptions intensify and support for EU-led initiatives increases. The chapter further situates Bulgaria within the wider debate on EU strategic autonomy and transatlantic relations. Ultimately, the chapter concludes that Bulgaria is well positioned to contribute to the emergence of a European Security and Defence Union, not as a substitute for NATO but as a complementary pillar. Achieving this, however, will require sustained investment, deeper regional cooperation, and more effective public communication to align societal attitudes with strategic objectives.