Does China have interests in the potential British transfer of BIOT to Mauritius?
The Tangram | No 02.2025
This is the second Tangram from Observing China, where the leading China experts give a diverse range of succinct responses to key questions on the development of the People’s Republic of China (PRC).
What do the United Kingdom (UK), the United States (US), Mauritius and the People’s Republic of China (PRC) all have in common? They are all keeping a beady eye on a sprinkling of remote islands in the Indian Ocean, in excess of 1,000 miles away from the next nearest landmass. Until late last year, many had never heard of the British Indian Ocean Territory (BIOT), made up of the Chagos Archipelago of islands. If one were to look closely at a map, it might seem that the UK, US and Mauritius were fighting over breadcrumbs. But if one zooms out, it might make sense as to why.
It is thought that Donald Trump, President of the US, may ask His Majesty’s (HM) Government to cancel the deal agreed late last year to cede control of the Chagos Islands to Mauritius. The American decision is because the most important island – Diego Garcia – is home to a large military base, shared by the UK and the US, and one of the most important military bases in the world for power projection.
John Bolton, former National Security Advisor during Trump’s first term, warned of a ‘coordinated’ effort by both Tehran and Beijing in carrying out ‘clandestine activities’ in Mauritius to wean the Chagos Islands away from its current oversight by Euro-Atlantic nations.
Last week, Iran’s ambassador in the region visited Mauritius to discuss academic exchanges and collaboration – US national security advisors have pointed out Iran’s history of using academia as a front for espionage and warned that should the islands be returned to Mauritius, Iran will most certainly find a way to gather intelligence on the Diego Garcia military base.
But what about Beijing? Does the PRC really have such a vested interest in the Chagos Islands, and if so, what is it?
Shadow Minister for National Security and Chair of the Advisory Council, China Observatory
The BIOT debacle demonstrates how multilateral organisations set up in good faith are no longer neutral arbiters of international disputes. While a world where all countries engage with and accept fair judgement would be ideal, the reality is that politicisation, and uneven implementation of rules is benefitting autocracies. Universalist organisations do not produce fair results when selective global powers ignore and hijack them to pursue national aims. One should compare the UK’s approach to BIOT with the PRC’s militarisation of the South China Sea.
The International Court of Justice (ICJ) ruling on BIOT is non-binding and based on the expulsion of the Chagossians in 1968. It does not address the current reality in which no agreement exists amongst Chagossians for Mauritian sovereignty.
In 2021, Mauritius enacted an extra-territorial law threatening ten years of imprisonment to anyone disputing Mauritian sovereignty over the islands. Chagossians who dispute Mauritian sovereignty could face prison if they return to their homeland after a deal is concluded.
While Chair of the Foreign Affairs Committee, I held meetings with Chagossians of all views. They felt that HM Government was not consulting them. David Lammy, Foreign Minister, has still not met them.
Effectively, HM Government is offering to pay eye-watering sums of money to Mauritius, which threatens imprisonment to Chagossians who dispute their claim, while ignoring many Chagossian voices because of a non-binding decision at the ICJ.
Over the last decade, the PRC has created and militarised dozens of islands in the South China Sea. Naturally, the BIOT would be an attractive proposition for Beijing. The PRC has unilaterally shifted its maritime zone into the internationally recognised waters of Brunei, Indonesia, Malaysia, the Philippines, and Vietnam.
In 2016, the PRC refused to participate in the international tribunal brought against it by the Philippines; actions of the Chinese Communist Party (CCP) in Tibet, Hong Kong and Xinjiang similarly show a total unwillingness to engage with multilateral organisations. No judgment will impede Chinese neo-imperialism.
By abandoning any sense of national interest or holistic justice, and focusing solely on a decision made on a narrow set of interpretations of past events, the surrender of the Chagos Islands would shift the balance of power towards the actively imperialist PRC.
The UK must awaken to the fact values it considers universal, such as freedom of navigation and freedom of expression, are under threat. The very framework established to protect them is riddled with efforts to undermine it. Combatting this threat must come from a place of strength – which requires Britain to hold onto its strategic assets, none more so than BIOT.
Otherwise, the UK will arrive at a point where the very bodies established to defend aspirational universalist values helped to manifest a new global order dominated by states whose conduct, at home and abroad, contradicts even the most basic of rights. Britain cannot simply sit back and allow this perversion to occur.
Senior Fellow, Paul Tsai China Centre
To understand why the PRC has much to gain, and Britain and America have much to lose, from the potential transfer of the BIOT to Mauritius, one must remember three key facts. First, positive global governance has always been provided by the combination of international law and the power necessary to enforce it. International law lends legitimacy to the exercise of power but is never a substitute for it.
Second, the world is increasingly unstable. Today, authoritarian states reject the restraints of international law and are undertaking expansionist policies. Russia attacked its neighbors in violation of law’s most fundamental prohibition against aggression. Iran employed proxy terrorist groups to expand its regional influence. The PRC ignored its dispute settlement responsibilities to take control of its neighbors' rights in the South China Sea.
Third, each of these states uses the desire of the free and open nations to adhere to international law against them. This is the essence of Russia’s hybrid warfare, the PRC’s maritime gray zone operations, and Iran’s terror tactics. In sum, the world is a dangerous and unstable place because authoritarian powers are ignoring international law and using violence to expand their influence.
Against this backdrop, the BIOT provides British and American power, and that of their allies, a vital geographic bulwark against the decline of global order. To leave a power vacuum for Beijing to fill – even by abandoning the Chagos Islands other than Diego Garcia – would seriously weaken Britain and America’s capacity to employ the power necessary to keep order in the region in accordance with international law, and to support allies and friends such as Australia, India, Malaysia, and Singapore.
If allowed, Beijing will act swiftly to build a base to challenge Britain and America’s influence, to secure its vulnerable supply lines, and to guard its western territories, which extend as far as the border of Pakistan. If international law is to have any chance to provide global stability, Britain must recognise the vital relationship between law and power and retain all of the Chagos Islands.
Expert Associate, National Security College, Australian National University
In this era of a deteriorating world order, control of maritime trade routes and strategic waterways has become a focal point of competition. The Indian Ocean, in many ways, is at the heart of this shift, with countries vying for strategic dominance. And at the heart of the Indian Ocean lies the BIOT.
In this context, the UK's transfer of the BIOT could inadvertently bolster Beijing’s growing influence in the region, potentially granting it future access to the strategically vital archipelago in the worst-case scenario.
Following the ICJ advisory ruling in 2019, it has become increasingly difficult for the UK to maintain its claims while advocating for international law in other forums, particularly against Beijing’s actions in the South China Sea.
Strategic competition in the Indian Ocean centres on control of sea lanes, which handle two-thirds of global oil shipments and one-third of bulk cargo. The PRC has invested heavily in ports and airports across the region, from East Africa to Pakistan, Sri Lanka, and Bangladesh. This includes over £1.2 million in Chinese foreign direct investment in Mauritius in 2022 alone. Other forms of investment include a 20-year loan from Beijing for the construction of Mauritius International Airport, completed in 2013.
While Mauritius has received direct investment from the PRC, it appears more closely aligned with India, which would likely oppose Chinese access due to its own strategic interests. However, a shift in the balance of power, potentially resulting from the UK's handover, could create an opportunity for greater Chinese influence. Beijing’s pattern of investment across the region indicates its interest in such opportunities. Although a full-scale base is unlikely, it is possible that the PRC could establish some level of infrastructure to maintain access and enhance its ability to surveil activities in the archipelago, including around Diego Garcia – although there is no evidence to date of any plans for this to be achieved.
If the deal proceeds, the UK will need to collaborate with Mauritius and India to mitigate the potential for Chinese access.
Parliamentary Researcher at the House of Commons
Yes, Beijing does indeed have strong interests in the transfer of the BIOT to Mauritius.
The BIOT is remote, large, and extremely easy to secure. It is made up of seven atolls and sixty islands, spread over 640,000 square kilometres, and boasts a marine protected zone. The waters are regularly patrolled and unauthorised boats are caught quickly by the Royal Marines.
However, with the transfer to Mauritius – who want to exploit the islands economically – it opens the door for fishing rights to be offered to Beijing in the waters around the base. This could allow the PRC to spy on the installation at Diego Garcia through fishing ships.
For decades, the PRC has used fishing ships as an extension of its military. Known as the Maritime Militia, first used in the South China Sea in the 1970s, their role has only expanded as Beijing has pursued aggressive operations around the South China Sea. The ships operate as commercial fisheries – providing plausible deniability – but double up as mini spy ships providing vast amounts of data to the People’s Liberation Army (PLA), the PRC’s armed forces, from the location of submarines to the activities at ports.
In the past, these ships have encroached on military vessels such as the USNS Impeccable in 2009, or floated on the fringe of economic exclusive zones of rival countries such as India.
In the eventuality that the PRC is ever granted development permission on the other islands, it would be entirely fitting with the BRI for innocuous infrastructure to be built packed with military surveillance equipment aimed directly at the base – not an uncommon tactic for Beijing; see the incident at the headquarters of the intergovernmental organisation African Union.
While Mauritius is an ally of India, that could quickly change once the transfer goes through, as the espionage opportunities are too good for the PRC to pass up.
Senior Lecturer in National Security Studies, King’s College London
The PRC has significant interests in the potential transfer of the BIOT to Mauritius, shaped by strategic, geopolitical, and postcolonial considerations. The Chagos Archipelago’s location, near key shipping lanes and home to the UK-US military base on Diego Garcia, makes it a vital strategic asset. This is often how small islands become subjects of great power interests (e.g., historical British bases in Malta and Singapore, and American bases in Iceland, or more recently Djibouti hosting both the US and the PRC, etc.). If sovereignty is transferred to Mauritius, this could create opportunities for Beijing to enhance its influence in the Indian Ocean Region, contributing to its broader maritime and geopolitical ambitions.
The PRC-Mauritius relationship is central to this dynamic. As a partner in the PRC’s Belt and Road Initiative (BRI), Mauritius currently benefits from substantial Chinese investment in infrastructure and trade. Beijing has also supported Mauritius’ claims to Chagos at the United Nations (UN), aligning with its longstanding narrative of anti-coloniality and efforts to champion solidarity in the so-called ‘Global South’. This support of Mauritius’ claims can therefore position the PRC as an ally of postcolonial justice, enhancing its image while countering the Euro-Atlantic dominance.
For Mauritius, the relationship with Beijing likewise offers economic and diplomatic leverage in asserting its sovereignty over Chagos. Chinese investments in Mauritian infrastructure and trade partnerships strengthen Mauritius’ economic resilience, which is critical as the nation navigates the legacies of colonialism and climate-induced vulnerabilities. Additionally, Beijing’s vocal support can amplify Mauritius’ position in international fora, particularly in its asymmetrical confrontation with free and open nations.
However, while the PRC’s support can add weight to its negotiating capacity, closer ties can also risk complicating its relationships with other important partners, including India and the US. Mauritius must tread carefully to assert its diplomatic position while balancing the broader geopolitical implications for many other regional players as well.
Grace Theodoulou – Policy Fellow, China Observatory
Email: grace@geostrategy.org.uk
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