Germany can co-finance European nuclear deterrence

With Donald Trump’s open support for Russia and his turning away from Europe and NATO, the question of the credibility of the American nuclear promise has taken center stage.

Unlike during Trump’s first term in office, however, this time Europe has recognized the dramatic nature of the situation and developed ideas to strengthen the British and French nuclear deterrent. Both European nuclear powers want to intensify their nuclear consultations and, in addition, French President Emmanuelle Macron has once again called for a dialogue between nuclear and non-nuclear states in Europe.

Germany is open to such a dialogue. The German British Defence Agreement (Trinity House), concluded in autumn 2024, already explicitly provides for an exchange on nuclear issues.

Friedrich Merz, Germany’s designated chancellor, also spoke out in favor of the nuclear dialogue proposed by Macron at an early stage. The idea of such talks is to send a signal of commitment and determination not only to Moscow, but also to Washington.

This is not (yet) about replacing the American “extended deterrent” with a European version as it is far from certain that Washington will close the nuclear umbrella over Europe, especially as the damage to the USA itself would be considerable.

The goal of nuclear non-proliferation, which America has always pursued, would be jeopardized and new nuclear states could emerge in Eastern Europe or Asia, for example.

However, the Trump administration is not known for taking the negative consequences of its own impulsive actions into account in advance.

What could Germany bring to such talks, and what would be its contribution to strengthening a European nuclear deterrent?

There’s certainly nothing along the lines of Germany attempting to develop its own nuclear weapons. Germany has repeatedly and formally renounced this option and, apart from a few academics, there is no politically serious voice in Berlin that would want to change this – not to mention the enormous costs of such a project.

Even the conceivable possibility of stationing French nuclear weapons on German soil – similar to the U.S. nuclear bombs in deployed in Germany – is currently only a theoretical one.

Paris has not yet abandoned its long-standing skepticism towards the idea of a nuclear umbrella for non-nuclear allies and sees nuclear weapons as a strictly national matter.

Furthermore, France only has around 40 nuclear cruise missiles and the same number of land-based, nuclear-capable Rafale fighter-bombers. The rest of the approximately 290 French nuclear warheads are intended for use at sea – either from submarines or with Rafale bombers from the aircraft carrier “Charles de Gaulle.”

The British nuclear arsenal is stationed exclusively on submarines.

What Germany can offer London and Paris, however, is to contribute to the considerable costs of both countries’ nuclear capabilities.

Back in May 2017, the Scientific Service of the German Parliament analyzed the co-financing of foreign nuclear weapons potentials from the federal budget in a publicly accessible report.

This assessment was commissioned by parliamentarians because the question of the reliability of the American nuclear commitments had already arisen during President Trump’s first term in office.

The report concluded that the Nuclear Non-Proliferation Treaty (NPT), which has been binding for Germany since 1975, does not contain a ban on support or funding from non-nuclear states for nuclear powers. Nor can such a ban be derived from the Two-Plus-Four Treaty, in which Germany’s non-nuclear status is enshrined, or from general international law.

Only some international treaties on “nuclear-weapon-free zones” contain indirect prohibitions on assistance. However, Germany is not a party to such treaties.

Apparently, Germany has not yet provided such nuclear co-financing, even though there were occasional rumors that the Federal Republic had provided financial support for the development of Israel’s nuclear weapons potential in the 1950s and 1960s. However, such rumors have never been substantiated.

What follows from all this is that financial support for British or French nuclear deterrence is possible in principle. Of course, this would only take place if a direct link were established between the nuclear weapons potential of both countries and the security of Germany and Europe.

The corresponding benefits and counter-benefits would have to be set out in legally binding bilateral agreements. It is worth noting that the German Federal Ministry of Finance has already created a branch called “Geo-Economics and Security Policy” in order to assess the various financial implications of the new security challenges – this branch could conceptually assess the implications of such an agreement.

If Germany were to include such an option in the planned dialogue between nuclear and non-nuclear states, the talks would immediately be elevated to a politically concrete and presumably mutually beneficial level. It would also be an example of a strategically forward-looking German security policy – something that has not often been the case in Berlin in the past.

Karl-Heinz Kamp is an associate fellow of the German Council on Foreign Relations and was president of the Federal Academy for Security Policy.

由于唐纳德·特朗普公开支持俄罗斯，并疏远欧洲和北约，美国核承诺的可信度问题已成为焦点。

然而，与特朗普第一任期不同，这一次欧洲认识到了局势的严峻性，并制定了加强英法核威慑的方案。这两个欧洲核大国都希望加强核磋商，此外，法国总统马克龙再次呼吁欧洲核国家与无核国家开展对话。

德国对此类对话持开放态度。2024年秋季签署的《德英防务协定》（三一大厦协定）已明确规定就核问题进行交流。

德国候任总理弗里德里希·默茨也公开支持马克龙早期提出的核问题对话。他认为，此类对话旨在向莫斯科和华盛顿发出德国的承诺和决心信号。

这（目前）还不是要用欧洲版本取代美国的“延伸威慑”，因为华盛顿是否会对欧洲关闭核保护伞还远未可知，尤其是考虑到这对美国自身造成的损害将是相当大的。

美国一直追求的核不扩散目标将受到威胁，新的核国家可能会在东欧或亚洲等地出现。

然而，众所周知，特朗普政府不会事先考虑其冲动行为的负面后果。

德国能为这类会谈带来什么？它能为加强欧洲核威慑做出什么贡献？

德国绝对没有试图研发自己的核武器。德国已经多次正式放弃这一选项，而且除了少数学者之外，柏林没有任何有影响力的政治人物希望改变这一立场——更何况，这样的项目耗资巨大。

即使是像美国在德国部署核弹那样，在德国领土上部署法国核武器这种可能性，目前也仅仅停留在理论层面。

巴黎方面尚未放弃其长期以来对为无核盟友提供核保护伞的怀疑态度，并将核武器视为严格的国家事务。

此外，法国仅拥有约40枚核巡航导弹和相同数量的陆基核打击能力“阵风”战斗轰炸机。其余约290枚法国核弹头计划用于海上作战——从潜艇发射或由“戴高乐”号航空母舰上的“阵风”轰炸机执行。

英国的核武库全部部署在潜艇上。

然而，德国可以为伦敦和巴黎提供的，是分担两国核能力的巨额成本。

早在 2017 年 5 月，德国联邦议会科学服务部门就在一份公开报告中分析了联邦预算中对外国核武器潜力的共同资助情况。

这项评估是由议员们委托进行的，因为在特朗普总统的第一任期内，美国核承诺的可靠性问题就已经出现了。

报告总结指出，自1975年以来对德国具有约束力的《不扩散核武器条约》（NPT）并未禁止无核国家向核大国提供支持或资金。此外，既不能从确立德国无核地位的《二加四条约》中推导出此类禁令，也不能从一般国际法中推导出此类禁令。

只有部分关于“无核武器区”的国际条约包含对援助的间接禁止条款。然而，德国并非此类条约的缔约国。

显然，德国尚未提供此类核能联合融资，尽管偶尔有传言称，联邦德国曾在20世纪50年代和60年代为以色列发展核武器潜力提供过财政支持。然而，此类传言从未得到证实。

由此可见，原则上可以为英国或法国的核威慑提供财政支持。当然，这只有在两国核武器潜力与德国和欧洲的安全建立直接联系的前提下才会发生。

相应的利益和反利益必须在具有法律约束力的双边协议中予以明确规定。值得注意的是，德国联邦财政部已设立“地缘经济与安全政策”部门，旨在评估新安全挑战带来的各种金融影响——该部门可以从概念上评估此类协议的影响。

如果德国将此选项纳入计划中的核国家与无核国家对话，会谈将立即提升到政治上具体且可能互惠互利的层面。这也将展现德国具有战略前瞻性的安全政策——而这在柏林过去并不常见。

卡尔-海因茨·坎普是德国外交关系委员会的副研究员，曾任联邦安全政策学院院长。