We're about to enter a terrifying new era of nuclear proliferation

Telegraph

21-03-2025

Britain is modernising its nuclear arsenal. John Healey, the Defence Secretary, warned that Britain's nuclear weapons have the power to inflict 'untold damage' to any adversary that dares to attack it. Sir Keir Starmer simultaneously declared that Russia respects Britain's nuclear deterrent and praised Britain's transition from Vanguard-class to upgraded Dreadnought-class nuclear-capable submarines.
Britain's nuclear build-up was wholly expected. In April 2024, the Prime Minister declared that his commitment to Britain's nuclear deterrent was 'unshakeable' and 'absolute'. Sir Keir also insisted that he would be prepared to use nuclear weapons if Britain was under attack. Yet it is also indicative of a broader trend that reflects an increasingly insecure world order and waning confidence in U.S. security guarantees: a new nuclear arms race.
Poland is pushing for the transfer of U.S. nuclear weapons to its territory. If that cannot be achieved, Poland wants to be protected by the French nuclear umbrella. Incoming chancellor Friedrich Merz wants the British and French nuclear arsenals to protect Germany. Since Donald Trump's return to the White House, South Korean foreign minister Cho Tae-Yul has reignited discussions about building a domestic nuclear deterrent.
The onrush of countries pursuing nuclear deterrents can be explained by three factors. The first is the enduring impact of Ukraine's historical experience. When Ukraine achieved independence from the Soviet Union in 1991, it possessed the third largest nuclear arsenal in the world. Fearing potential economic blowback from the U.S. and its allies, Ukraine ceded its nuclear weapons in exchange for the 1994 Budapest Memorandum's security guarantees. Although Russia was a signatory to the Budapest Memorandum, it still proceeded to invade Ukraine in 2014 and 2022.
Would Ukraine's retention of a nuclear arsenal have prevented Russia's aggression? On the one hand, it is important to emphasise that Ukraine never exercised sovereign control over its nuclear arsenal. Ukraine also did not have escalation dominance over Russia in the nuclear sphere. When I interviewed Ukraine's first president Leonid Kravchuk in 2017, he emphasized that Russia had clusters of nuclear weapons in Nizhny Novgorod that would have overwhelmed Ukraine's capabilities. On the other hand, it is conceivable that the U.S. could have greenlit Ukraine's autonomy over its nuclear arsenal in the event of Russian aggression and thwarted a full-scale invasion.
The latter argument has much more sway in Kyiv. At the Munich security conference in February 2022, Volodymyr Zelensky expressed frustration about the insecurity that followed its unilateral nuclear disarmament. Now that Mr Trump has taken Nato membership and Article 5 security guarantees off the table, Mr Zelensky views a Ukrainian nuclear arsenal as the next best thing. Poland's nuclear umbrella aspirations align with this thinking.
The second factor is the collapse of the post-Cold War international arms control regime. Starting with Russia's contraventions and the U.S.'s 2019 withdrawal from the Intermediate-Range Nuclear Forces (INF) treaty, arms control treaties have lost their enforcement capacity. China resisted U.S. pleas to participate in new strategic arms reduction treaty (Start) negotiations to contain its nuclear arsenal and Russia's full-scale invasion of Ukraine torpedoed new Start inspections. Russia's incendiary wartime rhetoric has normalised the use of nuclear threats as a tool of deterrence.
The third is the growing nuclear ambitions of the Russia-China-Iran-North Korea authoritarian axis. Although Russia's nuclear modernisation drive has been hampered by technological shortfalls and sanctions-induced delays, China intends to have 1,000 nuclear weapons by 2030. North Korea has announced breakthroughs in nuclear-powered submarine development. Iran's inexorable pursuit of the nuclear bomb could lead to Saudi Arabia, the United Arab Emirates and Egypt pursuing similar deterrents.
While many countries might fear sanctions if they independently develop nuclear deterrents, they could circumvent this risk by enriching uranium to just under the threshold needed to produce a nuclear bomb. Germany and South Korea already possess much of the technological know-how needed to achieve this goal.
This trend would set off an arms race spiral that will be hard to contain. It is also a potent reminder of how the erosion of U.S. security guarantees is making the world less secure.