The Russian invasion of Ukraine was a watershed moment for NATO, particularly in how it discusses nuclear matters and deterrence. It was noted that before the invasion, there was an inhibition for NATO and member states to talk about nuclear deterrence , as it could be perceived as escalatory. There is now broad consensus on the necessity of nuclear deterrence and an increased willingness to discuss nuclear matters across the board.
One important example of this move towards nuclear consensus is Germany and its shifting nuclear debate. Before the Russian invasion, the public debate was focussed on disarmament and the risks associated with nuclear weapons, with German decision-makers reluctant to lead public debate on the role of nuclear forces and the benefits of nuclear deterrence. After the invasion, this dynamic flipped, with those supportive of nuclear deterrence becoming more prominent in the debate. This historic shift was represented in the Zeitenwende speech of February 2022, when German Chancellor Olaf Scholz announced that the German Government would be spending €100 billion to increase military spending. According to available polls, since 2022, the German public has become more supportive of nuclear deterrence, more accepting of Germany’s nuclear sharing role in NATO, and more concerned with the prospect of Russian nuclear escalation. The acquisition of the F-35, previously highly contested, became an uncontroversial decision in the post-invasion environment. Germany’s military support for Ukraine and investment in conventional forces and capabilities are also significant reflections of Germany’s increasing support of NATO defence and deterrence.
Finland and Sweden’s decisions to join NATO are another important demonstration of the shifting nuclear consensus and debate. The Russian invasion of Ukraine represented a key turning point: with accession, these countries will be coming under NATO’s nuclear umbrella for the first time, and increasing NATO’s presence in the High North. Within Sweden, in preparation for alliance membership, this has sparked important discussions about nuclear deterrence, and about balancing NATO commitments with promoting nuclear arms control.
Challenges remain for the Alliance in sustaining this level of consensus over the long-term. In the case of Germany, there is already evidence that a ‘bounce back’ to previous attitudes is beginning and that politicians might shy away from potentially controversial topics around deterrence and defence. It was suggested that long-term socialisation is needed to make this type of change entrenched. To encourage willingness and ability to engage with nuclear issues and in public debates on nuclear deterrence, more focus is needed on education, training, and support of politicians, academia, and think tanks.
Despite the emphasis on consensus, there are still important debates occurring, both inside and outside the alliance, on the role of arms control and its relation to nuclear deterrence. It was noted that though ‘arms control’ and ‘deterrence’ are often presented as at odds with each other, this is not the case, especially for NATO: arms control and deterrence are the twin pillars of strategic stability. The coherence between these two concepts needs to be emphasised. The Vilnius Communiqué was highlighted as a document that brings together the language of both the arms control and deterrence communities: arms control and defence, risk reduction and deterrence. On the other hand, the Treaty on the Prohibition of Nuclear Weapons (TPNW), and certain Allies’ observer status within it, was raised as a key challenge for the Alliance, given the TPNW’s incompatibility with NATO’s nuclear deterrence posture, especially in the current security environment. The TPNW further highlights the need for NATO to communicate to external audiences about nuclear matters.
Another potential source of debate is around NATO nuclear sharing. Currently, there is consensus on the maintenance and modernisation of NATO nuclear sharing and the DCA mission; however, there is disagreement on whether and how to broaden it. For example, whilst Poland has been vocal in its desire to take on a NATO nuclear sharing role, there are allies that oppose this. This question relates to a wider discussion about how to promote effective deterrence as opposed to engaging in provocative and escalatory behaviour. Future challenges to the Alliance’s unity are raised by Ukraine’s accession to NATO, and multilateral measures that exclude some of the Alliance, such as the European Sky Shield Initiative.