Trident and the perils of online misinformation

In an era where social media serves as a conduit for information, the risk of misinformation spreading is ever more present.

A tweet by esteemed Scottish journalist Ruth Wishart recently ignited debate over the control of Trident.

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While her concerns appear rooted in the question of national sovereignty—a subject of crucial importance to many—her statement is incorrect. Here we’ll look at why it’s crucial to be well-informed about such a high-stakes issue.

“We don’t have an independent nuclear ‘deterrent’ – we couldn’t deploy so much as a peashooter without US say so – but actually harbouring America’s own nuclear arsenal would be beyond the pale. Another reason to decouple from the Trident-loving UK.”

We don't have an independent nuclear "deterrent" – we couldn't deploy so much as a peashooter without US say so – but actually harbouring America's own nuclear arsenal would be beyond the pale. Another reason to decouple from the Trident loving UK.

— ruth wishart (@ruth_wishart) September 1, 2023

Though provocative and widely disseminated, the tweet perpetuates a common misunderstanding about the UK’s Trident missile system. Contrary to popular belief, the United Kingdom retains full operational control over its Trident missiles—a point confirmed by multiple official sources, including Freedom of Information requests.

However, the tweet muddies the waters of an already intricate debate, blurring the lines between public understanding and the realities of national defence.

A Brief Overview of the Trident System

The Trident missile system, operated by the Royal Navy, serves as the cornerstone of the United Kingdom’s strategic nuclear deterrent. Based on four Vanguard-class submarines, this complex system is designed for high levels of stealth and can remain underwater for up to three months. Below, we elaborate on its various components, history, and the unique features that set it apart, such as the absence of a permissive action link system and the concept of the “letters of last resort.”

The Trident system’s origins can be traced back to the Cold War, a period marked by heightened nuclear tensions. Replacing the Polaris missile system, Trident became operational in the mid-1990s with its Trident II D5 Submarine-Launched Ballistic Missiles (SLBMs) mounted on Vanguard-class submarines.

Each submarine is capable of carrying up to 16 Trident II D5 SLBMs, although the current policy limits each vessel to eight operational missiles. These missiles can reach targets over 7,000 miles away and are incredibly accurate, owing to advanced navigation systems. Each missile can also carry multiple independently targetable reentry vehicles (MIRVs), each with a yield of up to 100 kilotons.

Notably, the UK’s Trident system does not employ a permissive action link (PAL) system, which would require codes or hardware to enable a launch. This design feature means that the operational control is solely in British hands. A ‘two-person rule’ is observed at every operational level, from the Prime Minister down to the submarine crew, to minimise the risks of an accidental or unauthorised launch.

An intriguing aspect of the Trident system is the existence of the “letters of last resort.” These are handwritten instructions from the sitting Prime Minister, sealed and stored in each of the four Vanguard-class submarines. These letters outline the actions to be taken by the submarine commander in the event that the UK government has been incapacitated by a nuclear strike. The letters are destroyed unopened whenever a new Prime Minister takes office.

The Trident system undergoes routine upkeep and modernisation. While the missiles themselves are of American design and are leased from the U.S., British-designed warheads are fitted onto them.

The Complexities of American Involvement

Despite operational independence, the UK’s relationship with the US in terms of defence is undeniably intricate. Although Britain has the technical capacity to launch Trident without American consent, the political likelihood of this happening is another matter.

A recent report by the Defence Select Committee emphasised the unlikelihood of Trident’s use for any purpose other than to “give legitimacy to a US nuclear attack by participating in it.”

This interdependence is not simply technological but deeply rooted in strategic and diplomatic considerations.

Another circulating myth is that Trident missiles utilise American GPS and require US launch codes for activation. In fact, Trident employs a stellar sighting guidance system and inertial navigation, thus not requiring any GPS. Additionally, British Trident warheads can be launched under the command of a submarine commander, with the support of his crew, without any external coded authorisation.

In short, Britain could launch them without consulting the U.S. but such a situation would be very unlikely.

Why Ruth Wishart’s Tweet Is Inaccurate

Ruth Wishart’s tweet suggests that the UK “couldn’t deploy so much as a peashooter without US say so,” which is not accurate. Whilst it’s fair to argue that the UK would be unlikely to employ its nuclear arsenal without consulting its American allies, this is a matter of geopolitics rather than operational control.

The UK has full operational sovereignty over its Trident system and could technically launch it independently of the United States. By suggesting otherwise, the tweet distorts the realities of British defence capabilities and contributes to the spread of misinformation.

Although the UK technically possesses the independent capability to deploy its Trident missiles, there is a strong case to suggest that it would be unlikely to do so without prior American approval, owing to intricate geopolitical considerations. Nonetheless, to claim that Britain lacks any operational control over its Trident system is both misleading and counterproductive, only serving to propagate misinformation in an age already rife with it.

Hence, the onus falls upon us to exercise due diligence in ensuring that public discourse is informed and accurate, particularly when it pertains to matters of national security.