How Independent is Independent?
The British government’s announcement on 25 February that it is to develop a new warhead for the TRIDENT submarine-launched ballistic missiles that constitute the UK’s nuclear deterrent has raised the perennial questions of just how independent that deterrent is, and how independent it could be. Answering the first depends on how one defines independence and on the essential details of authentication and authorisation procedures that – for good reason – remain secret: answering the second requires an objective assessment of the UK’s technological and industrial capabilities.
If independence means that the British Prime Minister (PM) could order the firing of a nuclear weapon without having to consult the leadership of any other nation, the Royal Navy’s (RN) TRIDENT system probably does meet that definition.
In theory, it is possible that a missile could even be fired from an RN submarine without the PM’s authorisation – and against the government’s wishes – because the UK does not use a permissive action link security device. However, in practice this seems extremely unlikely because, by implication, it would require an entire command team to ‘go rogue’.
However, if independence means that the UK designs, constructs, operates and maintains the system without relying on any outside entity to supply vital components or services, then TRIDENT does not meet that definition.
The TRIDENT II D5 missiles currently in service are built in the US by Lockeed Martin and return to the US for servicing: the UK and US share a pool of missiles, but not warheads. The UK’s missiles are fitted with their warheads in the Coulport facility near the Faslane submarine base in Scotland.
British warheads are built in the UK by the Atomic Weapons Research Establishment, which is run by a UK/US consortium. The current warhead probably uses key components – including the arming, fuzing and firing system, the gas transfer system and the neutron generator – from the US W76, to which the design is thought to be closely related.
Similarly, the new warhead design may have much in common with the new US W93, which is to equip US TRIDENTs and the successor missile. However, the W93 and its British counterpart “will be two independent development systems,” according to Alan Shaffer, the Pentagon’s Deputy Undersecretary of Defense for Acquisition and Sustainment.
It is most likely, therefore, that the UK deterrent is operationally independent but reliant on the US from technological and industrial standpoints. There is no reason why Britain should not design and build all three elements of its deterrent – submarines, missiles and warheads – although it has not built ballistic missiles since the BLUE STREAK programme, designed in 1956-1957 and cancelled in 1960 in favour of the US-led SKYBOLT: the learning curve, therefore, would be steep.
Affordability is not in question, since the British government issues its own currency; so long as the technology and expertise are available in exchange for £ sterling, Britain can pay for it.
Peter Donaldson in London for MON