Replacing the UK’s nuclear deterrent: the long-awaited warhead decision

Since 2006 work has been underway on several programmes that will maintain the UK’s nuclear deterrent beyond the life of the current system. Much of the focus in that time has been on the delivery of the new Dreadnought class submarines, which are expected to enter service in the early 2030s. However, a decision on replacing the UK’s Mk4/A nuclear warhead has also been long-awaited and work on possible options has been ongoing. After an initial deferral in 2010, a decision was widely expected to be taken as part of the Government’s Integrated Defence and Security Review.

In February 2020, however, a US official disclosed the existence of a UK replacement warhead programme, which the Government subsequently confirmed in a Statement to the House. That revelation prompted widespread criticism that a decision appeared to have been taken without an official Government announcement or appropriate parliamentary scrutiny. Questions over the independence of the UK’s nuclear deterrent have once again risen to the fore.