He’s not even chancellor yet, but Friedrich Merz already wants to revolutionise European security. In a recent interview on German television, he called for a European nuclear umbrella, with the Federal Republic swapping US protection for the backing of Britain and France. His geopolitical gambit isn’t surprising: the current generation of European political elites has never experienced such a crisis of confidence in the transatlantic relationship, with Donald Trump smashing the certainties they’ve held dear since the fall of the Berlin Wall.
In practice, though, escaping Washington’s tentacles may prove hard. After all, America has reasons to keep Europe pliable, even as the terrifying strength of ICBMs mean the continent’s two nuclear powers may be reluctant to share. And though other states have tried to venture out from beneath the US umbrella, the White House can make or break a nuclear programme — even if proliferation could ultimately create a durable balance of power.
European worries over their US ally are nothing new. France’s secret nuclear programme was launched as early as 1954 — before Charles de Gaulle returned to power — as a hedge against the possibility that Washington might prove unreliable. Learning of the Eisenhower administration’s plans to scale back its strategic commitment to Europe, the then German Chancellor Konrad Adenauer also reacted with alarm, signalling through diplomatic channels that West Germany might be compelled to develop nuclear capabilities should American security commitments prove untrustworthy.
These days, though, the tenor of debate feels different: not least in the number of German politicians who have echoed Merz in calling for a pan-European nuclear deterrent. Former Foreign Minister Joschka Fischer is one example here; Manfred Weber, leader of the CSU, is another. Even the late Wolfgang Schäuble, a well-known budget hawk, suggested that Germany would be willing to finance a French nuclear umbrella. Over the Rhine, meanwhile, Emmanuel Macron has repeatedly proposed “Europeanising” France’s force de frappe, a point also made by former French presidents including Jacques Chirac and Nicolas Sarkozy.
In practice, though, escaping the US umbrella is easier said than done. Consider technology. Unlike Paris, London’s atomic arsenal is not fully independent. British submarines carrying nuclear warheads must return regularly to the US for maintenance: the technology is essentially American. What further undermines the credibility of Britain’s deterrent is that, last year, a second consecutive test of a nuclear-capable missile failed.
There’s a broader point when it comes to weapons capable of annihilating entire countries too: sovereignty. There is an inherently national dimension to the bomb that de Gaulle clearly understood: it concerns the very existence of the state that possesses it. In France, after all, opposition parties are outraged whenever Macron hints at opening a discussion on the “European dimension” of the dissuasion nucléaire. The entire political spectrum, from Le Pen to the far-Left, believe it’s crucial to national sovereignty, and therefore can’t be shared. Extended deterrence, then, remains a liberal myth. In a potential nuclear showdown, Macron would surely not risk Paris for Vilnius, just as Trump would not be willing to sacrifice Los Angeles for Tallinn.
Nor is that the only way sovereignty matters. In 2023, the historian Sumantra Maitra articulated the “Dormant Nato” concept, which amounts to a coherent articulation of Trump’s strategy toward the Western alliance. Tellingly, Maitra’s theory only briefly touches upon the issue of nuclear deterrence. It advocates stopping Nato expansion and shifting the burden of Europe’s defence onto Europe itself. That’s understandable: with Asia now Washington’s primary focus, the Europeans must take care of themselves, especially as they have the resources to spare. Yet despite recommending disengagement, Maitra argues that the US nuclear umbrella would continue to protect Europe.
Maitra is the epitome of a realist, and must recognise that extended deterrence is an illusion. So how can this strategic ambiguity be explained? Ultimately, it preys on European naivety. The belief that America has existential stakes in the transatlantic partnership is deeply ingrained in the Old World. Take Olaf Scholz, who opposed discussions about a European nuclear deterrent out of fear of straining relations with Washington.
It is likely that once the war in Ukraine ends, Europeans will revert to their stubborn belief that they live in a low-threat world, trusting that if the worst occurs, America will come to the rescue. This is convenient for Washington, as it seeks to maintain control over escalation within its alliance system, even under a “Dormant Nato” scenario. Nuclear proliferation in Europe would disrupt this, neatly explaining why Maitra’s America First pragmatism includes the empty nuclear guarantee.
“Europeans will revert to their stubborn belief that they live in a low-threat world”
Not everyone is as naive as the Europeans. Every country in Asia understands that the world has become dangerous. Japan retains latent nuclear breakout capabilities, maintaining uranium enrichment facilities and tonnes of weapons-grade plutonium. That is enough to build thousands of warheads. For years, this “technical deterrent” has allowed Tokyo to pressure Washington into reaffirming its security guarantees while also serving as an insurance policy in case Japan is ever abandoned by its ally.
Though South Korea doesn’t possess plutonium, it is the biggest civilian nuclear player outside of China and Russia. For years, a majority of the population has supported the idea of an independent deterrent. The nuclear-armed North Korea and China’s growing aggressiveness have created a strong societal consensus on the issue. Keep in mind that South Korea is also the only non-nuclear-armed country to have successfully fired submarine-launched ballistic missiles. This fact, as nuclear proliferation specialist Vipin Narang has put it, “makes one wonder” about what Seoul could do under pressure.
Of course, open nuclearisation would not only provoke outrage and sanctions, but also trigger a strong response from geopolitical rivals. For this reason, countries that factor nuclear insurance into their strategic calculations are likely to follow Israel’s path of covert proliferation. Isolated among adversaries, and thousands of kilometres from its closest ally, Israel has opted for nuclear opacity: while its bomb has never been officially acknowledged, its looming presence nonetheless shapes the actions of other states.
In Israel’s case, reliance on scientific talent and the principle of kdushat ha-bitachon — “the sanctity of security” — played a crucial role. The latter ensured that the Jewish State’s nuclear programme remained above partisan disputes. While Europe may not lack gifted scientists, it is difficult to imagine the same level of determination and unanimity among its political elites.
But such resolve can, again, be found in Asia. Through the Seventies, faced with growing doubts about US security commitments, Taiwan launched a secret nuclear programme. When Washington found out, Jimmy Carter ordered it shut down. Soon after, he terminated the defence treaties linking Washington to the island. Taipei was given only 24 hours’ notice, and was thrown into a state of total diplomatic shock. A few years later, Taiwan revived its secret nuclear scheme. This time, a defector revealed it to the Americans, who again pressured Taipei to dismantle it. Future historians may well regard this decision to be as important as the opening to China.
What Taiwan missed, in short, was the tacit support of the US. When Israel developed its nuclear arsenal, it dealt with Richard Nixon, who chose to look the other way. For their part, Nixon and Henry Kissinger did not view proliferation as inherently destabilising. Instead, they differentiated between friendly and hostile states. Kissinger believed that, in the end, every regional power would establish its own nuclear deterrent.
One can clearly ask: should proliferation be a desirable goal? The main argument in favour points to the Cold War, a period of “long peace” during which no direct conflict between great powers occurred. Many theorists argue that we owe this stability to the so-called “nuclear revolution” — the bomb fundamentally modified the behaviour of political elites in nuclear-armed states. Even the most irrational leaders start to act with prudence when confronted with the awesome threat of total annihilation. “The very fact that war could be total, in the sense of destroying both sides, means that the conflict of interest cannot be total,” says Robert Jervis, one of the key thinkers on the nuclear revolution.
To rephrase, nuclear powers just do not go to war against each other. A case in point is Pakistan and India. Before they acquired nuclear weapons, many feared that New Delhi and Islamabad would destroy each other. Yet contrary to expectations, peace ensued. According to former Singaporean diplomat Bilahari Kausikan, this may be the path to future stability in Asia: ensuring a balance of mutually assured destruction between the US, China, Russia, the two Koreas, and Japan, effectively freezing the geopolitical chessboard. “This path will be fraught with tensions and even danger,” Kausikan has noted. “But the end result will be stabilising for the region.”
Perhaps. But the future of the nuclear revolution will ultimately depend on the instincts of whoever is in the White House. The choice between Nixon’s bold pragmatism and Carter’s risk aversion will shape the world order for years to come, whatever Friedrich Merz may wish.
