The failed Trident test highlights an imbalance in UK defence strategy

Failed tests may help the UK improve the reliability of its independent nuclear deterrent. But such events raise concerns about a lack of investment in non-nuclear defences.

Expert comment Published 26 February 2024 Updated 9 May 2024 3 minute READ

A recent test of Trident, the UK’s nuclear missile system, saw the missile fail to follow its planned flight path and fall into the ocean not far from where it was fired. The previous UK test in 2016 also failed, with the missile veering off course. 

The UK’s Ministry of Defence (MOD) maintains that Trident remains reliable as there is additional data from successful Trident tests by the United States military, backing up the missile’s reliability. 

Of course, the MOD needs to message that failed tests do not adversely impact the credibility of the UK’s deterrence posture. However, two tests in a row which did not go according to plan raises questions about the reliability of the UK’s overall system: why does it encounter difficulties which the US system does not seem to experience? 

The MOD will undoubtedly use the insights this test has provided to improve reliability: missile tests that go wrong are often more helpful than successful tests, as they produce important information that might otherwise be overlooked. 

But the incident does highlight a potential imbalance in the UK’s wider defence strategy. The UK has ringfenced its nuclear weapons capabilities in recent years despite further cuts to other parts of its military capabilities. 

A visible and understood ability to be able to fight and win using conventional weapons is a vital piece of any deterrence strategy. 

The primary function of nuclear weapons is to deter war – and specifically nuclear war – between nuclear adversaries. But the Cold War was a different environment to today’s complex security environment, in which most nuclear-armed states have more than one nuclear competitor to deter, and many non-nuclear weapons states possess significant non-nuclear military capabilities. 

The Russian war against Ukraine has further put the UK approach in question by demonstrating the warfighting capabilities that will be required in any future conflict – showing that a visible and understood ability to be able to fight and win using conventional weapons is a vital piece of any deterrence strategy. 

Conventional war-fighting need

The UK, as a major participant in NATO, needs to invest in foundational, useable, necessary equipment such as shells and ammunition – which right now would also provide further supplies for Ukraine. 

UK ammunition stockpiles are running low, and the amount invested in replenishing them is insufficient. Equally important is manufacturing equipment such as drones, long-range precision strike and other newer military capabilities which the UK does not yet possess or does not have in sufficient quantities.   

There are other elements of the UK’s industrial base which require urgent attention, such as the steel industry and the capacity to produce ammunition. 

The UK industrial base stands to benefit from some additional planned investment in conventional and new technology defence capabilities. Trilateral defence projects such as GCAP (to develop a new stealth fighter with Japan and Italy) and AUKUS (to create a new nuclear submarine with the US and Australia, and jointly invest in other technologies) are important investments in UK defence, high tech and port industries. 

But there are other elements of the UK’s industrial base which require urgent attention, such as the steel industry and the capacity to produce ammunition.     

21st century deterrence

The UK, like many of its NATO allies, has an urgent task to think through what deters in the 21st century. 

Any adversary would assume that the UK’s nuclear weapons could retaliate in the event of a nuclear attack. However, nuclear weapons are not able to prevent an adversary from disrupting critical national infrastructure or engaging in other types of grey zone warfare. 

Much could be learned from countries such as Finland or Switzerland, which have a much higher level of societal readiness, civil defence and resilience to such disruption than the UK.

UK deterrence could also be meaningfully strengthened by investing in increased early warning capabilities, and new proven conventional systems.

The Russian invasion of Ukraine has shown that the threat environment in Europe has shifted significantly in scale, scope and urgency.

To remain a reliable NATO partner, and to live up to its ambition, the UK needs to take stock of its approach to deterrence and defence, increase its understanding of conflict prevention measures and make the right investments for the future. It is not too early to invest in those capabilities now – but leave it any later and it may be too late. 

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Procurement and production processes can be long, but conventional weaponry can be produced more rapidly. Any new systems – particularly if they are nuclear or incorporate new, untested technologies – will have long lead times and likely costly overruns. 

Impact of Ukraine

The Russian invasion of Ukraine has shown that the threat environment in Europe has shifted significantly in scale, scope and urgency. 

Russia’s government has made nuclear threats since the start of the invasion, highlighting the risk of nuclear war in Europe and rekindling the debate in countries such as Germany and Poland about the need to acquire nuclear weapons for their own defence – particularly as they fear a lessening commitment from the United States. 

Similar voices are being heard in Asia over the threats from North Korea and upward shifts in China’s nuclear weapons numbers and platforms, and in the Middle East over long-term fears of Iran’s direction of travel. 

To complement its position as a non-proliferation champion, the UK does need to develop stronger integrated deterrence capability.

The UK is in a position to play an important role in increasing European and global security. It has been a stalwart defender of nuclear non-proliferation over many decades. It has worked with other countries to bring about the Joint Comprehensive Plan of Action to curb Iran’s nuclear programme, and it has supported the IAEA and global ban on nuclear weapons tests. It has also demonstrated a sustained commitment to multilateral disarmament measures. 

However, to complement its position as a non-proliferation champion, the UK does need to develop stronger integrated deterrence capability, by investing in new defence technologies and improving its own societal resilience – demonstrating a visible and verifiable ability to fight alongside NATO partners in the kind of wars Europe might face in the near future.