March 18, 2021 – Britain will grow its nuclear stockpile by a third, to 260 warheads, to ensure its security in a more risky global environment while facing new threats from states with conflicting values.
Prime Minister Boris Johnson outlined the foreign policy overhaul saying the UK would have to “relearn the art” of competing against countries with “opposing values.”
The United Kingdom has a purely sea-based nuclear arsenal, comprising four nuclear-powered, ballistic-missile submarines (SSBNs). The overall cap on the number of warheads had been due to drop from 195 to 180 under previous plans drawn up by the Labour Government’s Strategic Defence Review (SDR) of 1998.
Under the SDR, at least one Vanguard-class SSBN is on patrol with up to 16 Trident II D-5 missiles sharing up to 48 warheads at any given time. The warhead, known as the Holbrook, is manufactured at the Atomic Weapons Establishment (AWE) at Aldermaston, Berkshire.
In late 2016, the construction of four new Dreadnought class SSBNs started at the Barrow-in-Furness shipyard — the £31 billion (US$40 billion) successor to the Vanguard-class boats which carry Trident.
A revelation by Admiral Charles Richard, commander of US Strategic Command, in February 2020, confirmed that the UK is developing a new nuclear warhead to replace the Holbrook at the AWE. That caused a stir in the UK, as high-profile programmes like the atomic deterrent are usually announced in Parliament first.
Johnson’s announcement comes despite the UK being a signatory of the Non-Proliferation Treaty, which commits the government to gradual nuclear disarmament under international law.