UK ratchets up nuclear spending, with new warhead and delivery planes in the works

VIENNA — Britain will pour more than £63 billion ($84 billion) into its nuclear deterrent over the next four years, the government confirmed this week.The June 30 announcement comes as part of a £15 billion ($20 billion) defense funding boost announced by outgoing Prime Minister Keir Starmer’s government. It is a continuation and concretization of the U.K.’s recent push to expand the country’s atomic arsenal. The money will fund the Dreadnought-class ballistic missile submarines and SSN-AUKUS attack boats, along with a new sovereign warhead named Astraea, according to the announcement.The nuclear spending is a significant portion of a broader £298 billion ($398 billion) four-year spending profile meant to lift U.K. defense spending to 2.7 percent of GDP en route to NATO’s 3.5 percent target by 2035.The figures continue an upward trend in nuclear spending that has persisted for several years. The Ministry of Defence’s Defence Nuclear Enterprise already consumed 18% of the defense budget, £10.9 billion ($14.6 billion), in 2024-25, and the Public Accounts Committee had projected that share would keep climbing to a full fifth of all military spending. The International Campaign to Abolish Nuclear Weapons has separately calculated that Britain became the world’s third-largest nuclear spender in 2025, at $12.6 billion. The high spending associated with the nuclear program has caused criticism by some domestic advocacy groups who argue the money could be put to better use elsewhere. The government argues the nuclear bombs are essential to ensure Britain’s sovereignty, and that London plays a “unique role as the only European power to pledge our nuclear deterrent to defend our NATO allies.”Central to the current package is Astraea, the warhead designated A21/Mk7 that the Atomic Weapons Establishment has been developing since 2020 to replace the aging Holbrook design carried on Trident II D5 missiles. Officials and independent analysts say the replacement is less a matter of