Sweden, NATO and the Nuclear Question

Wednesday 11 February 2026

Recent remarks by the Swedish prime minister concerning closer cooperation within NATO on nuclear matters have reopened a debate that Sweden once considered firmly settled. For much of the Cold War Sweden maintained a posture of armed neutrality, combining strong conventional defences with an explicit rejection of nuclear weapons on her soil. Accession to NATO has altered the strategic framework within which Swedish security policy is formulated, even if it has not yet overturned the political reflexes inherited from decades of non-alignment. The question is no longer whether Sweden participates in a nuclear alliance, for she plainly does, but rather how far that participation might extend in practice.

In what follows we consider several plausible scenarios under which nuclear weapons might be hosted on Swedish territory, ranging from symbolic integration to permanent basing, and assesses their strategic, political and legal implications.

Historical constraints and inherited doctrine

Sweden’s historical aversion to nuclear weapons is not merely rhetorical. During the Cold War serious internal debates took place about developing an indigenous nuclear capability, but these were abandoned in favour of conventional strength and diplomatic credibility. By the time Sweden acceded to the Nuclear Non-Proliferation Treaty, her political culture had largely internalised the notion that nuclear weapons were both destabilising and morally suspect.

These instincts remain strong. Opinion polling consistently suggests deep public scepticism towards nuclear deployment, even as support for NATO membership has consolidated. Any move towards hosting nuclear weapons would therefore represent not an incremental adjustment, but a qualitative shift in Swedish defence identity.

Scenario one: political alignment without physical deployment

The least controversial scenario is one in which Sweden participates fully in NATO’s nuclear planning and consultative mechanisms without hosting weapons on her territory. Several NATO members already occupy this position. Under this model, Sweden would contribute to alliance deterrence through intelligence sharing, command integration, infrastructure support and political endorsement, while maintaining a formal prohibition on basing nuclear weapons.

Such an arrangement would align with Sweden’s existing declarations that she does not seek nuclear weapons on her soil, while still signalling to Moscow that Sweden is no longer a peripheral actor in Northern European security. The deterrent effect would be indirect, but politically significant, particularly in the Baltic Sea region.

Scenario two: contingency hosting in crisis or war

A second, more ambiguous scenario would involve contingency arrangements allowing for the temporary deployment of nuclear weapons to Swedish territory in the event of a severe crisis or armed conflict. This model would mirror Cold War practices in several NATO states, where nuclear weapons were not permanently stationed but could be moved rapidly if required.

From a strategic perspective, Sweden’s geography makes her an attractive location for such contingency planning. Her territory offers proximity to the Russian Northern Fleet, access to the Arctic approaches, and depth for the defence of the Baltic states. From a political perspective, however, even temporary hosting would be difficult to reconcile with long-standing assurances given to the Swedish public. The distinction between permanent and temporary deployment may appear clear to strategists, but is unlikely to carry much weight in domestic debate.

Scenario three: nuclear sharing arrangements

A more far-reaching possibility would be Swedish participation in NATO’s nuclear sharing arrangements, under which non-nuclear states host US nuclear weapons and provide delivery systems, while ultimate control remains with Washington. This model currently applies to several European NATO members.

For Sweden, this would entail profound legal and political adjustments. It would require not only the physical basing of nuclear weapons, but also the integration of Swedish air forces into nuclear delivery planning, training and certification. While such arrangements are compatible with NATO doctrine, they sit uneasily with Sweden’s traditional interpretation of her obligations under the Non-Proliferation Treaty, even if they are formally compliant.

Domestically, nuclear sharing would almost certainly provoke parliamentary resistance and popular protest. Internationally, it would be interpreted by Russia as a major escalation, particularly given Sweden’s proximity to key Russian military assets.

Scenario four: permanent basing as part of Northern European deterrence

The most radical scenario would involve the permanent stationing of nuclear weapons on Swedish territory as part of a broader restructuring of NATO’s northern deterrence posture. This might be considered if the security situation in Europe were to deteriorate dramatically, for example following the collapse of existing arms control regimes or a major escalation in the war in Ukraine.

Such a move would transform Sweden from a security consumer into a front-line nuclear host state. The strategic logic would be clear. Permanent basing would enhance NATO’s second-strike resilience and complicate Russian planning. The political cost, however, would be immense. Sweden would become a priority target in any nuclear exchange, and her long-standing reputation as a voice for arms control and restraint would be severely weakened.

Legal and diplomatic implications

Any hosting of nuclear weapons would require careful navigation of Swedish constitutional law, alliance commitments and international obligations. While NATO does not require members to host nuclear weapons, it does expect solidarity in deterrence policy. Sweden’s challenge lies in reconciling these expectations with domestic legal norms and political culture.

Diplomatically, Sweden would also need to consider her role within the Nordic region. Cooperation with Finland, Denmark and Norway would be essential, particularly given regional sensitivities surrounding nuclear deployment and the risk of divergent national policies undermining collective credibility.

Conclusion

Sweden’s entry into NATO has not compelled her to abandon her traditional caution towards nuclear weapons, but it has undeniably narrowed the space in which that caution can be exercised. Of the scenarios considered, political integration without physical deployment, remains the most consistent with Swedish public opinion and historical identity. Contingency arrangements, while strategically attractive, would test domestic consent. Nuclear sharing or permanent basing would represent a profound redefinition of Sweden’s role in European security, likely achievable only in the context of a far darker strategic environment than exists today.

The prime minister’s remarks should therefore be understood less as a prelude to imminent deployment than as an acknowledgment of strategic reality. By joining a nuclear alliance Sweden has accepted that nuclear deterrence forms part of her security, even if the precise manner of her participation remains deliberately, and perhaps prudently, unresolved.