The UK’s Surrender of Chagos is a Symptom of Strategic Ineptitude

The British Indian Ocean Territory comprises over 1,000 islands in the centre of the Indian Ocean and has been controlled by the UK since 1810 when it was seized from the French. Prior to French-led settlement, the islands were uninhabited. The territory has hosted a strategic military base since the 1960s and constitutes one of the largest marine protected areas in the world. But on 3 October 2024, London ceded sovereignty over the islands to Mauritius. The move demonstrates worrying strategic ineptitude in a world that the UK government describes as being characterised by great power competition.

Succumbing to Lawfare

Those defending the UK’s surrender of sovereignty would make three observations in defence of the deal. They would argue that after a UN General Assembly vote pushing for the UK to cede control, followed by an advisory ruling from the International Court of Justice (ICJ) to the same effect, the UK risked a binding ruling being passed against it. If forced to cede the territory under these conditions – they argue – the UK would suffer a greater blow to its soft power than if it conceded graciously, and might struggle to retain control over the military base. Instead, the deal that was struck leaves the UK with rights to the base for 99 years. Defenders of the deal would therefore also argue that the government preserved its strategic interests while resolving a diplomatic dispute that was causing friction with countries across the Global South. 

There are several problems with this view. That Mauritius orchestrated an effective campaign to have various countries vote against the UK’s sovereign control of the territory does not alter the fact that Mauritians have never controlled it themselves. The French and British administered Mauritius and the Chagos Archipelago as one territory under their respective colonial administrations. This is the basis of the ICJ advisory opinion that they should be returned to Mauritius, but this would if anything affirm rather than nullify an artefact of colonialism. 

French plantations had been established on the Chagos Archipelago in the 18th century. The great irony, however, is that while the UK evicted the Chagossians in the years following 1967, the deal struck with Mauritius does nothing to address the forced displacement of this population and does not take their wishes into consideration. What Mauritius has done is successful lawfare; creating a diplomatic problem to try to gain control over economically valuable territory that it wants to exploit.

An important aspect of this lawfare campaign is that the coalition supporting Mauritius was not cohered by strong interests in the cause but because a number of countries hostile to the UK, including but not limited to Russia, carried out significant diplomatic legwork to ensure Mauritius had support. Russia saw this issue as a way of imposing costs on the UK, and it seems to have succeeded.

These factors are important because the belief that this has drawn a line under the issue is wrong. Firstly, while the UK could have simply continued to assert its sovereignty, it has now created a legal precedent that will be used by other states to try to make predatory claims on British territory elsewhere. And countering such lawfare will – by virtue of the precedent set – be more difficult. Secondly, precisely because the coordination against the UK was carried out by competitors trying to impose costs on the UK, they are not going to stop pushing in this direction now that the UK has ceded sovereignty. They will simply move on to the next issue. 

The arguments about ‘securing’ the UK base are spurious because the base was secure prior to the ceding of sovereignty. Indeed, the proposition is audacious given that in fact the deal makes the base less secure in absolute terms, and diminishes part of its strategic value.

Strategic Self-Harm

The base at Diego Garcia is extremely remote and consequently comparatively safe from enemy interest beyond space-based observation. Moreover, because the UK holds the surrounding islands and has made the sea-space a marine protected zone, it is very difficult for competitors to have monitoring equipment emplaced near the facility. A patrol ship with a Royal Marine detachment on board has routinely policed these waters, detaining illegal fishing boats and other intruders.

By ceding sovereignty, the UK has given Mauritius – which has a stated ambition to economically exploit the territory – the ability to grant fishing rights and other navigation rights to the waters surrounding the base. As the base is home to US long-range bombers, it is of considerable interest to China. Beijing uses its fishing fleet as the eyes and ears of its military, with Chinese fishing boats routinely equipped with sensors and communications equipment to monitor other countries. There is a significant risk that such vessels will soon ply the waters around the base. It is worth noting that the Foreign, Commonwealth and Development Office was already routinely preventing the prosecution of Sri Lankan fishing vessels illegally fishing in the marine protected area, even when they were detained by the patrol vessel and found to be carrying sophisticated radar, for fear of causing diplomatic tensions. 

Another issue is that if Mauritius wishes to economically exploit the archipelago, it will need to establish infrastructure on the islands. The most likely investor in such projects is China, and based on what China has done elsewhere in the Indo-Pacific, its state-owned enterprises will allow it to have pre-staged equipment at these sites that, if an escalation were to occur over Taiwan – for example – could contribute to disrupting operations from Diego Garcia.

Putting aside grave questions about this decision, it is also relevant to note that the UK is currently undertaking a Strategic Defence Review, as well as an audit of its policy towards China. Neither process has concluded. Depending on the result, Diego Garcia may be more, or less important. But the government has pre-empted its own strategy, ensuring that this decision has no coherence with a wider approach to the country’s security. It should be noted that while the Conservatives have sought to make political hay over this issue, the negotiations to bring this policy about were initiated on their watch.

In summary, therefore, the UK has ceded strategic ground when it did not have to and received nothing in return. It has done so in a manner that is not aligned with a wider strategy. It has also invited competitors to apply pressure elsewhere, while diminishing the security of a strategic base. This is nothing short of self-harm. 

The views expressed in this Commentary are the author’s, and do not represent those of RUSI or any other institution.

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