AI applications raise complex ethical, legal, and security challenges that demand comprehensive and coordinated governance at multiple levels. In this paper, we examine how key European Union (EU) regulatory frameworks, such as the AI Act, GDPR, and NIS2, interact to set standards for AI security, functionality, and ethical performance. By comparing the objectives and requirements outlined in these regulatory instruments, we identify points of convergence that encourage a holistic approach to creating transparent, accountable, and fair AI systems. This alignment is pivotal for building user trust and mitigating risks associated with data breaches, algorithmic bias, and privacy violations. Moreover, we explore how harmonizing these regulations can maintain the EU’s competitive edge in AI innovation, as clear governance structures help businesses remain agile while protecting consumer interests. Our analysis further addresses the ramifications for global AI governance, emphasizing the significance of a unified, forward-looking strategy to ensure responsible AI development. In doing so, we recommend future harmonization initiatives that promote societal well-being, safeguard human rights, and uphold ethical and technological standards worldwide. Find more information here: https://link.springer.com/article/10.1007/s43681-025-00749-x