The Bang Behind the Buck: Replacing the UK’s Nuclear Warheads

While the UK’s nuclear submarines begin to approach the end of their service life, the warheads that arm them may last long into the future. Successive governments have been happy to reassure the public of their reliability, and have left politically and financially difficult decisions over their future to subsequent parliaments.

However, an investigation of the UK’s warhead programme suggests that its future is dictated more by the US than by imperfect predictions of reliability. Unfortunately, the US may be just as unpredictable.

Drawing upon what open sources are available on the UK’s nuclear arsenal, this paper outlines its composition and status and describes how it might ultimately be replaced or renewed. It finds that a limited understanding of warhead ageing makes it is extremely hard to quantify the confidence that can be held in any assessment of a warhead’s longevity, and in the absence of a clearly fatal flaw, the arsenal will depend more upon external rather than internal factors.

Chief amongst these external factors will be the US warhead programme, which provides many key components of the UK arsenal. But the UK may have no more luck predicting the future of the US programme than it does the reliability of its own arsenal. The US programme is currently in flux, and is likely to remain so for the foreseeable future. And with more resources at its command, any changes to the US programme may outstrip the UK’s ability to keep up.

About the Author

Hugh Chalmers is a Research Analyst within RUSI’s Nuclear Analysis Programme.