The Debate in Germany

The turn of 2023 and 2024 saw the intensification of public debate about the strengthening of nuclear deterrence by European states independently of the U.S. Discussions on this topic have been mainly taking place in Germany, where they began in 2016 over concerns about the future of U.S. commitment to NATO. Uncertainty on the issue has been compounded by renewed warnings from Donald Trump, the former one-term U.S. president and candidate in this November’s election, that he would not defend Alliance countries that spend too little on defence. The discussion about European nuclear deterrence also has been invigorated due to Russia’s 2022 invasion of Ukraine, backed by nuclear threats.

German politicians have been much more involved in the nuclear debate in recent months than before. The differences of opinion between them are not determined by party affiliation. The idea of a joint European nuclear deterrent was supported by, among others, the president of the EPP faction in the European Parliament, Manfred Weber (CSU), the SPD’s lead candidate in the European Parliament elections, Katarina Barley, or the former foreign ministers Joschka Fischer (Greens) and Sigmar Gabriel (SPD). Vice-Chancellor Robert Habeck of the Greens described the idea as unrealistic, while SPD members Chancellor Olaf Scholz and Defence Minister Boris Pistorius criticised the discussion on alternatives to the U.S. and NATO nuclear deterrence as premature and harmful. Roderich Kiesewetter, a parliamentarian specialising in security policy from the CDU/CSU, the largest of Germany’s opposition parties, spoke in a similar vein. He criticised other proposals as insufficient, expensive, and encouraging the U.S. to reduce its commitment to the Alliance. In turn, Finance Minister and FDP leader Christian Lindner called for discussions on increasing the French and British contributions to the nuclear deterrence in NATO.

Germany’s potential acquisition of its own nuclear weapons has not met with the support of German politicians, although CDU President Friedrich Merz has not ruled out discussing the subject in the future. This idea, promoted by some commentators, have been criticised by German experts as being contrary to Germany’s international obligations and entailing the risks of sanctions, worsening relations with allies and provoking further nuclear proliferation or even a Russian preventive attack.

A European Nuclear Deterrent?

Calls for the creation of a joint European nuclear deterrent most often vaguely envisage the “Europeanization” of France’s nuclear forces within the EU. These ideas are, however, unrealistic because France does not propose any sharing of control of its nuclear arsenal, even in exchange for co-financing, nor do any other nuclear-weapon states. Moreover, unlike the U.S. and the UK, France does not formally extend its nuclear deterrent, that is, it does not explicitly declare that it could use nuclear weapons to defend its allies. One of the main rationales for France’s acquisition of nuclear weapons capability in the 1960s was precisely the distrust of such assurances by the U.S. France demonstrates its independence by not participating in NATO’s Nuclear Planning Group (NPG). At the same time, President Emmanuel Macron has declared ambiguously since 2020 that French “vital interests” and the nuclear forces that protect them have a “European dimension”. This can be interpreted as the possibility of France using its nuclear weapons not only to defend its own territory. But this could also mean the conviction that its independent nuclear deterrence makes France more willing to assist an ally with conventional forces without fear of enemy retaliation.

Even if there was an agreement on creation of a European nuclear arsenal, its effectiveness and credibility would be limited by a number of political, military, and legal problems. This was demonstrated by the failed attempts to establish a NATO multinational nuclear force (MLF) in the 1960s (it was to entail ships with American nuclear missiles and crews from various countries). For example, the more countries that have the right to co-decide on the use of such potential, the greater the risk that one of them would veto such a decision. Moreover, the EU is an inadequate forum for dialogue on strengthening nuclear deterrence in Europe. The Union includes the states parties to the Treaty on the Prohibition of Nuclear Weapons (TPNW): Austria, Ireland, and Malta. In turn, the United Kingdom, which has a nuclear arsenal, is outside of the EU.

Possibilities for Strengthening the French (and British) Deterrence

A more feasible way to strengthen the European nuclear contribution to deterring Russia would be to utilise the national deterrents of France and the UK. A stronger emphasis on the willingness to use nuclear weapons to defend allies would be served by strengthened rhetoric, especially France’s making a clear declaration to that effect. Another way of such signalling would be more frequent demonstrations of nuclear capabilities in cooperation with allies. France would have wider possibilities to do so. Compared to the UK, it possesses not only submarines with intercontinental ballistic missiles but also multirole aircraft capable of carrying nuclear cruise missiles.

Even with enhanced signalling, the credibility of the British and French nuclear forces in extending deterrence to allies would still be limited by their size. France has nearly 300 nuclear warheads and the UK has up to 260. Even if they decided to significantly expand their nuclear forces, it would likely take many years due to the limited production capacity of both countries. Meanwhile, the U.S. arsenal counts almost 4,000 nuclear warheads and Russia possesses even more. The relatively small size of the French and British nuclear forces raises questions about the extent to which these countries could use some of them to respond to attacks on allies without decreasing the forces needed to deter strikes on their own territories (France assumes the possibility of conducting only a single warning nuclear strike before a massive retaliation). The much larger and diverse U.S. force is not only more flexible in this respect but also provides more possibility for signalling commitment to extended deterrence, including through nuclear-sharing. As part of the latter, the U.S. has been stationing nuclear bombs in a few NATO countries, probably around 100 warheads. If approved by the U.S., they could be dropped by allied aircraft in wartime.

Conclusions and Recommendations

So far, the debate on creating a European nuclear deterrence independent of the U.S. has not produced a consensus on its feasibility or actions to be taken by the European states. The trigger for further-reaching deliberations on this topic would most likely only come if the U.S. were to take radical steps, such as exiting NATO, withdrawing its nuclear weapons from Europe, or drastically reducing the conventional military presence there. European allies will not be able to quickly provide an extended nuclear deterrent with a credibility similar to that of the U.S. For Poland and other NATO members, the current model remains optimal, with the U.S. playing the key role and the nuclear arsenals of France and the UK complementing it. Nonetheless, a positive response from European countries to Macron’s 2020 offers of dialogue on the contribution of French nuclear forces to collective security and for allies to associate with nuclear exercises could further complicate Russian calculations while improving the understanding of nuclear deterrence matters in Europe. Association with French exercises should include not only observing them but also the participation of Allied conventional forces as support for the nuclear mission. A more frequent presence of French nuclear-capable aircraft on NATO’s Eastern Flank is also desirable. In addition, it could be beneficial to initiate a similar nuclear dialogue with the UK. Also, consultations with both countries could facilitate more far-reaching steps should the U.S. radically reduce its role in NATO. However, European countries should first and foremost make efforts to reduce the risk of the Americans making such a decision. This goal would be supported by further enhancing the European allies’ involvement in deterring Russia by significantly strengthening the conventional forces and the contribution to nuclear-sharing with the U.S.