Rafael Loss, European Council on Foreign Relations, writes:
America’s credibility is in tatters. According to ECFR’s latest public opinion poll, fewer Europeans than ever consider the United States under President Donald Trump “an ally that shares our interests and values”. This shift has been building since at least February 2024, shortly after Trump encouraged Russia to attack “delinquent” US allies on the campaign trail—an intervention that crystallized fears about Washington’s reliability and fuelled Europeans’ desire for alternative models of nuclear deterrence.
Britain and France, Europe’s two nuclear-armed NATO allies, are central in the resultant conversations. Britain’s nuclear weapons have long been committed to the defence of the alliance, whereas France’s deterrent sits outside of the NATO framework. As such, French president Emmanuel Macron’s address on nuclear deterrence, which is due to take place on March 2nd, is sure to draw particular scrutiny.
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America’s eroding credibility means that it remains necessary for France and Britain to retain their nuclear forces, especially when considering future NATO security. However, to become instruments of non-proliferation or escalation management, they require development. To borrow from the latest US Strategic Posture Commission, French and British nuclear forces—as the core of a future European strategic deterrent—likely need to grow in size and change composition (or both) to account for structural changes in US defence strategy and Trump-specific hits to US credibility. But they would not have to replicate the US posture to achieve this.
Moreover, France, Britain and their European partners would also have to agree on joint rhetoric and actions to signal resolve and capability in European deterrence. This is not only to assure each other, but also to deter potential adversaries.