EU-NATO influences on Portuguese nuclear policy

Decoding Portugal’s role in nuclear multilateralism

Despite significant EU and NATO influences, Portugal's approach to nuclear issues is far more encompassing. Why is Lisbon's broader multilateral approach vital?

Nuclear weapons have once again become a central component of international politics, with limitations on their development and stockpiling having weakened. Several states aim to expand their nuclear capabilities, and others might want to acquire them. What role does Portugal, a small Euro-Atlantic state with a colonial past and a global outlook, play in a domain mostly relevant to major powers?  How does it define its nuclear policies?

To answer these questions, the researchers used a triangulation of official policy documents, secondary literature, and interviews with 11 officials. Despite significant European Union and NATO influences, Portugal’s approach to nuclear issues is far more encompassing. Lisbon’s overarching preference for international cooperation better explains its role and policies.

Portuguese foreign policy

Portugal, a diminutive state situated on the western edge of Europe, prioritises its involvement in the European Union (EU) and NATO within its foreign policy agenda. Additionally, it maintains significant ties with Portuguese-speaking nations, stemming from its historical connections with former colonies.  Embracing a tradition of global engagement, Portugal aspires to bolster its political significance and overcome its small territorial size and semi-peripheral position by fostering multilateral relations and bridging diverse regions.

Can small states contribute to the “nuclear weapons complex” and lower nuclear risks? The case of Portugal demonstrates that the country’s integration in the European Union and NATO are not enough to explain Portuguese entrepreneurship in nuclear agendas.

Sandra Fernandes
Credit. Midjourney

Nuclear arms control

Several treaties, institutions, and mechanisms exist to facilitate multilateral cooperation regulating nuclear weapons. Foremost among these is the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), which is complemented by the International Atomic Energy Agency (IAEA), the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), various United Nations (UN) agencies, and other entities. Both the European Union (EU) and NATO, as multilateral frameworks themselves, also address nuclear weapons concerns.

The NPT delineates nuclear non-proliferation as the “prevention of wider dissemination of nuclear weapons” and nuclear disarmament as the “total absence of nuclear weapons in their respective territories.”

The proliferation of nuclear weapons poses an escalating and existential threat. Relations among nuclear powers are deteriorating, and the pace of nuclear disarmament is decelerating amidst advancing technology and heightened competition.  These factors, compounded by regional tensions and persistent interests in acquiring nuclear weapons or materials for their construction, have elevated the risk of nuclear weapons use to levels reminiscent of the Cold War era.

EU-NATO influences on Portuguese nuclear policy

The influence of the European Union (EU) and NATO on the formulation of Portuguese nuclear policy is evident. Portugal actively engages in initiatives of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) and the International Atomic Energy Agency (IAEA), funded and organized by the EU, as noted in interviews. Additionally, Portugal employs diplomatic démarches to encourage small Portuguese-speaking nations to sign and ratify multilateral agreements on nuclear weapons.  Furthermore, Lisbon’s participation in training and outreach programs on nuclear proliferation, organized by the EU, has led to significant enhancements in its national legal framework concerning the export control of proliferation-sensitive technologies. Viewing nuclear issues as secondary concerns, Portugal aligns itself easily with common EU positions, as indicated in interviews.

However, Portugal’s paramount priority remains ensuring that its obligations to NATO are upheld, both within the EU and beyond. As NATO is a nuclear alliance, Portugal is committed to remaining under its “nuclear umbrella.” Consequently, Portugal staunchly supports NATO’s incremental approach to disarmament and opposes the Treaty on the Prohibition of Nuclear Weapons, as highlighted in interviews. The country actively participates in NATO military exercises featuring nuclear scenarios and engages in scientific projects and outreach initiatives focused on nuclear non-proliferation.

Broader multilateralism as a primary preference

Nonetheless, Lisbon also engages in diplomatic initiatives within the framework of the NPT and supports the CTBTO and the IAEA independently from EU channels. Moreover, it actively participates in outreach endeavors to promote the universal adoption of nuclear treaties and regulations, extending beyond the confines of NATO and the EU.

Portugal has collaborated with various nations, including those within the Portuguese-speaking community, in non-proliferation efforts led by the United States. Emphasizing the United Nations as the primary forum for multilateral collaboration, Portugal advocates for increased coordination among international bodies in nuclear affairs. It perceives nuclear non-proliferation, disarmament, and the peaceful utilization of nuclear energy as interconnected priorities that reinforce one another within multilateral frameworks.

Overall, Portugal demonstrates policy convergence between its actions within the EU and NATO and its engagements within other multilateral forums. This suggests that Euro-Atlantic influences play a less distinctive role. At the core of Portugal’s nuclear policy formulation lies a steadfast commitment to international cooperation across all levels. While the EU and NATO coexist alongside other multilateral entities, they collectively contribute to a broader framework of multilateralism. It is this broader preference for multilateral engagement that best elucidates Portugal’s role in the nuclear domain and the shaping of its nuclear policies.

Key findings

This study provides insights into how different national orientations interact or overlap in foreign policy formation. While the EU and NATO largely influence Portugal’s actions in the nuclear sphere, the country operates within their parameters. However, while they allow Lisbon to increase its involvement in nuclear matters, many contributions taking place in EU and NATO contexts also occur elsewhere, that is, in other multilateral settings.

These multilateral frameworks do not prevail over one another but complement and reinforce each other. The country is a relentless promoter of multilateralism in solving nuclear weapons issues. In essence, Portuguese nuclear policies are fundamentally multilateral, yet they underscore Portugal’s Euro-Atlantic ties and its affinity towards the Portuguese-speaking world.


Journal reference

Fernandes, S., & Ferreira, D. S. (2023). Portugal in the nuclear realm: a case of broad ‘multilateralization’. International Politics, 1-22.

Sandra Fernandes is an Assistant Professor with Tenure at the University of Minho (Portugal). She holds a PhD in Political Science from Sciences Po (Paris). Her research interests include European studies, the post-Soviet space, the relationship between the European Union and Russia, foreign policy analysis, international security, and multilateralism. She has published books, book chapters, and papers, including: "Institutional Inertia and Change: Explaining the Czech and Portuguese Engagement in European Defence Market Integration," Journal of Common Market Studies (2023, with T. Weiss and M. Pisklová).

David Silva Ferreira is a Portuguese PhD candidate in Political Science at the University Institute of Lisbon (Iscte). He holds a master’s degree in international studies from the same institution. His research interests include nuclear deterrence, non-proliferation, and disarmament; American foreign and domestic politics; U.S.-Russian relations; and security studies. He is a researcher at the Centre for International Studies (CEI-Iscte) and was awarded a scholarship from the Portuguese Foundation for Science and Technology. He recently published: "The US Nuclear Policy during the War in Ukraine" (Relações Internacionais no. 77, 2023).