The Trump administration has consistently shown disregard for America’s European allies, whether it be in the Oval Office or at the Munich Security Conference. The administration’s actions have led France, and other U.S. allies, to push for a European-led nuclear deterrent. Regardless of any debate over U.S. reliability, a European deterrent is economically, technically and politically inadvisable.
Whether the United States actually seeks to distance itself from the North Atlantic Treaty Organization (NATO) alliance, as some have suggested, or is trying to bully allies into increasing their self-reliance for defense, misses the point — Europe already thinks it is in a position that requires it to seek new options for strategic security.
America’s NATO allies underspent on their militaries for decades. U.S. presidents of both parties have repeatedly asked them to step up. Russian aggression in Ukraine was a clear wake up call, and European allies have raised their military commitments since 2022. Although Europe’s increased defense spending was long overdue, increasing nuclear capabilities is not. Decision makers on both sides of the Atlantic should be clear-eyed about the effects this potential shift in global nuclear policy would have for the future security of the United States and Europe.
The Infeasibility of a French-Led Deterrent
France is the most vocal about leading a European nuclear deterrence effort. However, nuclear weapons are extraordinarily expensive, labor intensive and extended deterrent infrastructure requires extensive technical cooperation. Currently, France maintains a minimal nuclear deterrent mostly based around submarine-based weapons. The kind of nuclear expansion that could replace U.S. security guarantees in Europe would require extraordinary economic and political investment from France and other countries interested in being covered by the umbrella.
Though a French-led nuclear deterrent would not necessarily mean nuclear proliferation from other countries in Europe, it would almost certainly require nations without nuclear weapons to participate in active economic, scientific, political and military support of France’s nuclear expansion. This would upset Moscow’s traditional balance of forces calculation and could provoke a Russian response. A French-led deterrent only serves to trigger more dangerous and unnecessary global nuclear competition in a time of already increased tensions.
From a technical perspective, NATO nuclear sharing functions because U.S. nuclear capabilities are the “supreme guarantee of the Alliance’s security” and any final nuclear decisions are made by the U.S. President. American nuclear weapons in Europe therefore play a political rather than military role and serve as the physical manifestation of the U.S. commitment to NATO.
Nuclear decision-making for the French-led deterrent would be much more complicated. Germany and Poland are just two countries that have noted their interest in the French umbrella. France, Germany and Poland may align on the security environment in Europe now, but this has not and will not always be the case. French nuclear forces are a national asset, and it would require an unprecedented policy shift to allow for any sort of nuclear sharing arrangement similar to the one currently provided by the United States.
Political and Economic Risks of a European Nuclear Deterrent
There are additional complications. For instance, Germany has a powerful cultural taboo against holding nuclear weapons and weapons of mass destruction (WMDs) generally — a reluctance rooted in the legacy of militarism that produced horrific human rights abuses during World War II, many of which were perpetrated against Polish citizens. In the past, NATO’s nuclear mission has been controversial for the public across Europe, and would likely prove so again. Expanding European nuclear capabilities now, even under French leadership, would require engagement from entire countries’ infrastructures — as such, public opinion and resistance should not be discounted when assessing a European deterrent’s feasibility.
A credible European deterrent could also take more than a decade to achieve. This means there could be a significant period during which Europe is left without NATO nuclear sharing or its own deterrent. Therefore, the United States would have to decide how far its “support” would go. Would the United States be willing to act as a backstop for European nuclear deterrence until a European deterrent finally came online? If not, America’s abandonment of previous commitments could create permanent distrust and resentment in the transatlantic relationship, transforming former partners into potential adversaries. Why would the United States want resentful countries engaging in massive nuclear expansion? And why would Russia stand by and let them?
Additionally, a European-led deterrent would require a massive investment in new capabilities for weapons production, new nuclear warheads and integrated communications. As an example, the United States spends $75 billion each year to modernize its own nuclear arsenal. That is more than multiple NATO allies spend annually on their entire defense. This level of investment would add to what is already a fraught European economic environment in which countries across the continent are facing increased deficits and national debt. The outcome could be further political instability.
Stability for the United States Requires Stability in Europe
A French-led nuclear deterrent cannot replace U.S.-led NATO nuclear sharing. Regardless of any concerns over U.S. reliability, a French-led nuclear deterrent is economically, politically and technically infeasible and inadvisable for both American and European security. If the United States really wants more long-term stability and less responsibility in Europe, it needs to support its European partners’ efforts to address their own nuclear and conventional security threats, most notably from Russia.
Conventional capabilities have defined the war in Ukraine, and NATO is already answering the call to increase its conventional spending. The United States should build on this success. Showing partnership in addressing Russian aggression in Ukraine and the Baltics will rebuild political faith, hardening Europe’s commitment to address its own security concerns.
A possible debate on European nuclear weapons could further empower political forces sowing disunity in Europe and risk eroding the largely stable and prosperous peace the continent (and the United States) has enjoyed for decades. There are too many nuclear weapons in Europe already. The U.S. (and NATO) policy priority should be to create conditions that will lead to a reduction in the number of nuclear weapons, rather than provide an excuse for France to build more.
While some in Europe have responded to uncertainty over the U.S. commitment to NATO by reconsidering a European nuclear deterrent, the reality is that stepping away from NATO commitments, including nuclear sharing, would not free the United States from international security obligations. Instead, it would reduce U.S. leverage over European allies and adversaries alike, potentially leading to more nuclear-armed states at a time when even President Donald Trump is calling for denuclearization.