Further complicating matters are several other nuclear states – Britain, France, India, Israel, North Korea and Pakistan – each with its own nuclear doctrine, geography, fears and political compulsions. Their arsenals are smaller, but the danger they pose is no less.
By Ana PALACIO
The nuclear issue has returned to the center of global politics. While the specter of nuclear proliferation never went away, it was overshadowed for decades by a functioning and predictable global order, supported by a hegemonic US, a strong NATO, and credible arms control regimes. But that order is now under unprecedented pressure, with the US-Israeli war on Iran as the latest evidence. How can we maintain nuclear deterrence in a world where its architecture is collapsing? The dawn of the nuclear age led to a reversal of strategic thinking. Until then, military power had been measured by the ability to win wars, which was tested on the battlefield. But the purpose of nuclear weapons was de-escalation, not victory. Nuclear weapons did not eliminate conflict. The Cold War remained violent, dangerous, and morally corrupt. Proxy wars erupted, and people lived in fear.
What nuclear weapons did was raise the stakes of conflict, with their mutual assured destruction helping to prevent direct war between the superpowers. Deterrence worked not because it made leaders virtuous, but because it made escalation suicidal.
That grim logic remains relevant, but its context has changed. Whereas the Cold War was essentially bipolar, today’s nuclear order is multipolar. China joins the United States and Russia as a major nuclear power. Although China’s arsenal remains smaller, the U.S. Department of Defense predicts that it could exceed 1,000 operational nuclear warheads by 2030. The result will not be simply an expanded version of the Cold War. Trilateral deterrence is more unstable than bilateral deterrence. Each great power must calculate not only its balance with adversaries but also how moves against one affect the other. Arms control becomes more ambiguous, and crisis management more complex.
Complicating matters further are several other nuclear states – Britain, France, India, Israel, North Korea and Pakistan – each with its own nuclear doctrine, geography, fears and political compulsions. Their armaments are smaller, but the danger they represent is no less. A nuclear exchange on the Korean Peninsula or between India and Pakistan would not only be a major Regional tragedy; it would affect wider alliances, disrupt global markets and supply chains, and reshape great-power calculations. But perhaps the most dangerous factor in the emerging nuclear order are the brinkmen. The risk is not just that more states build up large arsenals; it is that some acquire sufficient nuclear capabilities to believe they can intimidate neighbours, deter foreign intervention, or survive a conventional defeat. Just a few nuclear weapons could be enough to transform a Regional crisis into a global one.
This increases the importance of negotiations to end the war in Iran. A deal that brings about immediate military de-escalation and reopens the Strait of Hormuz could be diplomatically useful. But if it does not include a clear agreement on Iran’s nuclear program, the lesson learned – not only in Iran but also in Turkey, Saudi Arabia, South Korea and Japan – may be that proliferation is a good strategy. Europe is also paying attention. NATO’s collective defense clause remains the bedrock of European security, but it is not an automatic mechanism; it must be activated through political decisions. The more the European NATO countries doubt that the US will fulfill its commitment to come to their defense, the more they will defend themselves, through strengthening national capabilities, special bilateral guarantees and alternative nuclear means.
This is not a hypothetical prospect. While former Polish President Andrzej Duda called for the deployment of US nuclear weapons on Polish territory – an attempt at greater assurance that it can rely on the US nuclear umbrella – Prime Minister Donald Tusk has stressed the importance of autonomy in nuclear deterrence. Moreover, German Chancellor Friedrich Merz has been pushing for a common European nuclear umbrella, supported mainly by France and the UK. France certainly seems to be on board with the idea. In March, French President Emmanuel Macron outlined a doctrine of “advanced deterrence” that would cover the country’s European allies. Belgium, Denmark, Germany, the Netherlands, Greece, Poland, Sweden, Norway and the UK have already agreed to participate in the strategy, supporting France’s nuclear deterrent with their own conventional forces.
But France’s so-called nuclear “parapluie” is fundamentally limited – selective, sovereign and reversible. It does not cover all EU member states; it leaves out the inner circle of countries (like Spain); and it keeps nuclear decision-making entirely in France’s hands. Macron’s rhetoric suggests not the emergence of a truly European nuclear deterrent but an attempt to embellish burden-sharing with the language of strategic autonomy. After all, there is no substitute for the American security guarantee. But Europe must do its part to keep that guarantee politically viable. To that end, rather than going to the next NATO summit in Ankara with more anxiety disguised as indignation, European leaders should arrive with a commitment to strengthening the European pillar of the alliance.
This means expanding their conventional capabilities, strengthening their air and missile defenses, deepening their weapons stockpiles, improving their intelligence and surveillance capabilities, and increasing their contribution to deterrence below the nuclear threshold. The greater Europe’s conventional capabilities, the less the outcome will depend on America’s willingness to risk a nuclear escalation.
Crucially, this approach would also reduce proliferation pressure, which would be good news for the United States. The last thing the country wants is a world in which any worried ally or Regional power concludes that only nuclear weapons can guarantee its security. American ambiguity may be helpful to some extent; American abandonment would be fundamentally liberating. The nuclear age began with the understanding that victory could bring catastrophe. That risk remains as potent as ever, but the institutional frameworks that mitigated it have been severely eroded. The task now is to prevent the pursuit of non-aggression from leading to proliferation. For Europe, this means keeping the United States engaged, building conventional capabilities, preserving NATO’s credibility, and maintaining strategic deterrence.
(The author is a former Foreign Minister of Spain)