Three Gorges Dam
EnergyThe world's largest hydropower station by installed capacity, at 22.5 GW, and the main flood-control structure on the Yangtze.
Yichang, Hubei
Formerly administered as part of the British Crown Colony of Mauritius, the British Indian Ocean Territory (BIOT) was established as an overseas territory of the UK in 1965. A number of the islands of the territory were later transferred to the Seychelles when it attained independence in 1976. Subsequently, BIOT has consisted only of the six main island groups comprising the Chagos Archipelago. The largest and most southerly of the islands, Diego Garcia, contains a joint UK-US naval support facility. All of the remaining islands are uninhabited. Between 1967 and 1973, former agricultural workers, earlier residents in the islands, were relocated primarily to Mauritius, but also to the Seychelles. …
The National Infrastructure Index maps the physical assets national life runs on — power stations and grids, water systems, ports, railways and airports, data networks, payment systems and launch sites. Each asset is placed in a Strategic Infrastructure capability group, so it can be read against the ratings in the National Capability index above.
Assets are chosen for how much of the economy and state depends on them and how hard they would be to replace. Each card records what the asset is, the category it belongs to, what it does and where it is.
Example assets. These twenty cards are modelled on China's most critical infrastructure and show on every nation page until each nation's own assets are mapped.
The world's largest hydropower station by installed capacity, at 22.5 GW, and the main flood-control structure on the Yangtze.
A 16 GW dam on the Jinsha River, built around sixteen 1 GW turbines, the largest single units in service.
A ±1,100 kV direct-current line carrying 12 GW more than 3,000 km from Xinjiang's power bases to the eastern grid.
China's first large commercial nuclear plant, in service since 1994, with much of its output sold to Hong Kong.
A canal carrying Yangtze basin water more than 1,400 km north from the Danjiangkou Reservoir to Beijing and Tianjin.
The 1,318 km trunk line between the two largest cities, opened in 2011 and one of the busiest high-speed routes in the world.
The world's busiest container port since 2010, including the automated Yangshan deep-water terminals.
The world's largest port by cargo tonnage, handling iron ore, crude oil and coal for the eastern industrial belt.
The capital's second international hub, opened in 2019 around one of the largest single terminal buildings in the world.
A 55 km bridge and undersea tunnel system linking the western and eastern shores of the Pearl River Delta, opened in 2018.
The 1,956 km line from Xining to Lhasa, crossing the Tanggula Pass at 5,072 m, the highest railway in the world.
One of eight national data centre hubs under the East Data, West Computing programme, hosting major cloud providers.
A 2,000 km quantum key distribution trunk line through Jinan and Hefei, completed in 2017 for secure government and bank links.
CIPS clears and settles cross-border payments in renminbi, launched in 2015 to extend the currency's international reach.
The coastal launch site for Long March 5 heavy-lift rockets, used for the Tiangong station modules and lunar and Mars missions.
China's first launch site, founded in 1958 in the Gobi Desert, and the base for every crewed Shenzhou mission.
The national satellite navigation system, providing global positioning and timing since 2020 from its Beijing control segment.
The world's largest known rare-earth deposit and the core of China's rare-earth mining and refining supply chain.
A weir and channel system built around 256 BC that still irrigates much of the Chengdu Plain's farmland.
China's leading maker of 3D NAND flash memory, central to the drive for a domestic semiconductor supply.
The National Development Index tracks the events that move a nation's capability — policy decisions, technological milestones, economic turns and external shocks — and places each one on the record with the date it happened and what followed from it. It is the narrative counterpart to the indices: where a rating says where the British Indian Ocean Territory stands, the index says how it arrived there.
Recent developments cover the current cycle, close enough that their consequences are still unfolding. Historical developments are the inflection points behind the present position — the decisions and events a reader needs in order to read the ratings above in context.
Portuguese navigator Vasco da Gama surveyed the islands of the Chagos Archipelago, bringing them into European knowledge. The archipelago had previously been known to Maldivian mariners but was never permanently settled.
France asserted sovereignty over the archipelago in the eighteenth century, administering it as a dependency of Mauritius. This established the administrative link with Mauritius that the United Kingdom later inherited and eventually severed.
The first permanent inhabitants were African slaves and Indian contract labourers brought to found coconut plantations. Their descendants developed into the Chagossian people, with a distinct creole language.
British forces took Mauritius, and with it the dependent Chagos Archipelago. This transferred the islands from French to British control.
The Treaty of Paris formalised French cession of Mauritius and its dependencies, including the Chagos Archipelago, to the United Kingdom. British sovereignty over the islands dated from this settlement.
Abolition ended formal slavery on the plantations of what would become the BIOT, but former slaves continued working as indentured labourers. The plantation company retained effective control of inhabitants' lives until the 1960s.
The company acquired the copra plantations, consolidating commercial control of the islands. Company rule shaped the lives of the inhabitants for decades.
By 1900 the population comprised 426 families, 60 per cent descended from African-Malagasy slaves and 40 per cent from South Asian indentured labourers. Chagossian creole developed as their common language.
Military facilities including an airstrip were constructed on Diego Garcia during the war, then abandoned when it ended. This foreshadowed the island's later strategic use as a major base.
The Seychelles-based company acquired the copra plantations shortly before the British government's intervention. The plantations were the sole economic base of the islands' population.
The two governments opened confidential negotiations about establishing a base, with the United States requiring a territory without a local population. An earlier option, Aldabra, was dropped over ecological concerns, leaving Diego Garcia as the preferred site.
The UK split the Chagos Archipelago from Mauritius and Aldabra, Farquhar and Desroches from the Seychelles to form a new overseas territory for Anglo-American defence purposes. Mauritius was paid £3 million in compensation under pressure during independence negotiations, with a further £650,000 in 1972 for relocation costs.
Weeks after the separation, the UNGA declared that dismembering the colonial territory of Mauritius breached customary international law as set out in the 1960 Declaration on Decolonisation. The resolution underpinned Mauritius's later legal campaign for sovereignty.
The exchange of notes constituted the founding agreement making the BIOT available for defence purposes. Subsequent agreements covered a communications facility (1972), naval support facility (1976), construction contracts (1987) and a monitoring facility (1999).
Buying out the private plantations removed the islanders' economic base and enabled their removal. From 1967 Chagossians who had left the islands were prevented from returning.
Around 2,000 Chagossians were expelled from Diego Garcia, Peros Banhos and the Salomon Islands to Mauritius and the Seychelles. Diego Garcia was cleared in January 1971 to meet a US deadline, and the outer islands from June 1972; the UK told the UN the territory had no indigenous population to avoid reporting obligations.
Mauritius attained independence after the detachment of the Chagos Archipelago, becoming a republic within the Commonwealth in March 1992. Its independence settlement was later found by the ICJ to have been unlawfully incomplete.
Negotiations between 1971 and 1982 resulted in compensation for the displaced islanders, known as Chagossians.
The lease allowed construction of a major US military installation near oil shipping routes and Iran, countering Soviet influence. In return Britain received a substantial discount on Polaris nuclear missiles, making the deal strategically valuable to London.
Work began on a large airbase with long-range runways and a harbour for major naval vessels. Though nominally a joint UK/US base, it is primarily staffed by American forces with a permanent British garrison.
The three island groups were handed back days before Seychelles independence on 29 June 1976. Thereafter the BIOT consisted solely of the Chagos Archipelago.
The territory's waters were incorporated into the IWC's whale sanctuary. This was an early marker of the archipelago's environmental significance.
Mauritius argued the 1965 separation was illegal under international law, despite its apparent agreement at the time. The UK rejected the legal argument but undertook to cede the territory once no longer needed for defence.
The company was licensed to provide telecoms in the territory, later rebranding as Sure (Diego Garcia) Ltd after its 2013 acquisition by the Batelco Group. This established the territory's commercial communications infrastructure.
The Mauritian EEZ declaration encompassed the seas around the British Indian Ocean Territory and was formally protested by the UK. It marked an escalation of the maritime dimension of the sovereignty dispute.
The flag combined the Union Jack with wavy lines representing the Indian Ocean and a palm tree above the British crown. It gave the territory a distinct symbolic identity.
The base hosted nuclear-capable strategic bombers as a deterrent during the Gulf War. It went on to support the 2001 war in Afghanistan and the 2003 Iraq War, confirming its central role in Western power projection.
The zone covered the territorial seas of the BIOT, asserting British regulatory control over fisheries. It was one of a series of maritime governance measures contested by Mauritius.
Postage stamps, issued for the territory since 17 January 1968, had been denominated in rupees reflecting the Mauritian and Seychellois heritage. From 1992 they were issued in sterling, the territory's official currency.
The signature extended the agreement to the territory and was protested by Mauritius when it signed in 1997. Fisheries governance became a recurrent arena of the sovereignty dispute.
The Indian Ocean top-level domain was granted to a British entrepreneur and operated commercially as the Internet Computer Bureau until 2017, when it was sold to Afilias for US$70 million. In July 2021 the Chagos Refugees Group UK sought repatriation of the domain and back royalties.
Implementing legislation, including amendment of the British Nationality Act 1981, was suspended following opposition from US President Donald Trump. Ministers indicated ratification would not be sought in the current parliamentary session.
The territory's Supreme Court upheld the returning Chagossians' right of residence, reversing decades of exclusion. The territorial administration is appealing the ruling.
Four Chagossians, acting for the self-declared Chagossian Government, defied a British exclusion zone to set foot on the island without permission; six were reported to have returned. Served a removal order on 18 February, they obtained an injunction from the BIOT Chief Justice on 19 February preventing immediate deportation.
The US President publicly attacked the UK–Mauritius agreement as a sign of total weakness, later urging on Truth Social that Diego Garcia not be given away. His opposition proved decisive in halting the agreement.
Following an online consultation in which 1,233 of 1,341 voters supported the move, opponents of transfer to Mauritius established the Chagossian Government-in-Exile. It dropped 'in exile' from its name on 17 February 2026 after its leader returned to the islands, becoming a rival government.
The treaty would transfer sovereignty to Mauritius on entry into force, with the base remaining under British control for 99 years, extendable by forty more. US Secretary of State Marco Rubio welcomed it as securing the long-term operation of the joint facility.
The US President announced a blanket tariff applying to the territory. It illustrated the reach of American trade measures even over a territory hosting a joint US base.
Under the deal the UK would transfer sovereignty while administering Diego Garcia for at least 99 years, with resettlement of the other islands and a support fund. It drew criticism for bypassing Parliament and for excluding the Chagossian community from decision-making; new Mauritian premier Navin Ramgoolam rejected it on 17 December 2024 and sought fresh talks.
The British Foreign Secretary confirmed talks on the territory's sovereignty, with both states agreeing to preserve the joint UK/US base on Diego Garcia. Analysts linked the shift to strategic competition with China; the talks ceased in late 2023 when the Defence Secretary blocked the negotiated agreement.
A Mauritian expedition raised the Mauritian flag on Peros Banhos and surveyed Blenheim Reef for a forthcoming ITLOS hearing. The chartered vessel was shadowed by a British fisheries protection ship.
The island was linked by a spur to the new Oman Australia Cable running between Perth and Muscat, at a cost of $300 million. It substantially upgraded the territory's communications capability.
Eighty-nine Tamils intercepted in distress were escorted to Diego Garcia, with around 173 arriving in 2021 and 2022 and held in a fenced tented camp. The Refugee Convention does not apply to the BIOT; in December 2024 the BIOT Supreme Court ruled twelve had been unlawfully detained.
In a Mauritius–Maldives maritime boundary dispute the tribunal held that Mauritius is sovereign in the archipelago. The UK disputed and did not recognise the decision, but it added to the mounting international pressure.
The UPU required Mauritian stamps to be used instead on mail from the territory. It was a further erosion of the BIOT's international recognition.
The Court found that decolonisation of Mauritius was not lawfully completed and that the UK must end its administration of the Chagos Archipelago as rapidly as possible. On 22 May 2019 the UNGA adopted a supporting resolution by 116 votes to 6, sharply raising international pressure on London.
Mauritius won African backing and Brexit deprived Britain of European support, with allies including Canada, France and Germany among 65 abstentions. The referral set up the decisive advisory opinion of 2019.
The 1966 arrangement, in force to 2016, was extended for a further twenty years alongside a pledge of £40 million for former residents. The base was seen as important for managing growing Chinese influence in the Indian Ocean.
The UNCLOS tribunal found the MPA violated British obligations, as Mauritius held binding rights to fish in the waters, to eventual return of the archipelago, and to minerals and oil found there. The plan for a formal protected area was consequently dropped.
The Strasbourg court's decision did not favour the islanders' claims. It closed another avenue of redress following the House of Lords defeat.
The reserve covered the territory's EEZ and prompted mixed reactions from Chagossians, some fearing it would bar resettlement by preventing fishing. Patrols increased apprehensions of illegal vessels, but Mauritius challenged the MPA as contrary to its legal rights.
After failed negotiations with Mauritius in 2009, the Maldives lodged a claim overlapping both British and Mauritian zones, arguing uninhabited northern Chagos islands should not generate baselines. The dispute complicated the sovereignty question, and Maldives reiterated a claim to the islands in November 2024.
The British government won its appeal, overturning the lower courts and restoring the exclusion of the Chagossians from their homeland. The ruling closed the domestic legal route to return for many years.
On 11 May 2006 the High Court ruled the 2004 BIOT Constitution Order in Council unlawful, striking down the immigration policies that banned resettlement of the outer islands and entitling the Chagossians to return, while upholding the special military status of Diego Garcia. The Court of Appeal confirmed the ruling on 23 May 2007. The decisions were the high point of the islanders' litigation before their later reversal.
Exiled islanders travelled to the archipelago for humanitarian purposes, including tending ancestral graves. It was a rare acknowledgment of their ties to the islands.
The Order vested legislative power in the Commissioner and declared that no person has the right of abode in the territory, which was set aside for UK and US defence purposes. It reversed the post-2000 policy allowing resettlement of the outer islands.
The zone extended British environmental jurisdiction across the territory's exclusive economic zone. Mauritius opposed it and on 5 August 2005 reasserted its own declared EEZ around the territory.
From 2002 certain Chagossians became eligible for British citizenship. This improved their legal standing while leaving the question of return unresolved.
The court delivered the first of a series of legal victories for the exiled islanders. The British government responded by announcing that Chagossians could return to the archipelago other than Diego Garcia, a position reversed in 2004 before anyone moved.
Wetland protection obligations were applied to the territory, with application to non-military areas of Diego Garcia beginning on 4 July 2001. It formed part of the territory's growing environmental regime.
From 1998 the displaced islanders sought further compensation and the right to return to the territory through a series of court cases.
Formerly administered as part of the British Crown Colony of Mauritius, the British Indian Ocean Territory (BIOT) was established as an overseas territory of the UK in 1965. A number of the islands of the territory were later transferred to the Seychelles when it attained independence in 1976. Subsequently, BIOT has consisted only of the six main island groups comprising the Chagos Archipelago. The largest and most southerly of the islands, Diego Garcia, contains a joint UK-US naval support facility. All of the remaining islands are uninhabited. Between 1967 and 1973, former agricultural workers, earlier residents in the islands, were relocated primarily to Mauritius, but also to the Seychelles. Negotiations between 1971 and 1982 resulted in the establishment of a trust fund by the British Government as compensation for the displaced islanders, known as Chagossians. Beginning in 1998, the islanders pursued a series of lawsuits against the British Government seeking further compensation and the right to return to the territory. In 2006 and 2007, British court rulings invalidated the immigration policies contained in the 2004 BIOT Constitution Order that had excluded the islanders from the archipelago, but upheld the special military status of Diego Garcia. In 2008, the House of Lords, as the final court of appeal in the UK, ruled in favor of the British Government by overturning the lower court rulings and finding no right of return for the Chagossians.
archipelago in the Indian Ocean, south of India, about halfway between Africa and Indonesia
6 00 S, 71 30 E; note - Diego Garcia 7 20 S, 72 25 E
Political Map of the World
land area is about 0.3 times the size of Washington, DC
0 km
698 km
flat and low (most areas do not exceed two meters in elevation)
coconuts, fish, sugarcane
NA
archipelago of 55 islands; Diego Garcia, largest and southernmost island, occupies strategic location in central Indian Ocean; island is site of joint US-UK military facility
NA
tropical marine; hot, humid, moderated by trade winds
Capability-group ratings for Critical Technology are part of the GINC National Capability Framework rather than the country factbook. They are published in the National Capability index, and the per-capability detail lives on the capability pages.
1 (2013)
.io
75,006 (2012)
defense is the responsibility of the UK; the US lease on Diego Garcia expires in 2016
no regular military forces (2014)
no indigenous inhabitants
Mauritius and Seychelles claim the Chagos Islands; Negotiations between 1971 and 1982 resulted in the establishment of a trust fund by the British Government as compensation for the displaced islanders, known as Chagossians, who were evicted between 1967-73; in 2001, the former inhabitants of the archipelago were granted UK citizenship and the right of return; in 2006 and 2007, British court rulings invalidated the immigration policies contained in the 2004 BIOT Constitution Order that had excluded the islanders from the archipelago; in 2008 a House of Lords' decision overturned lower court rulings, once again denying the right of return to Chagossians; in addition, the United Kingdom created the world's largest marine protection area around the Chagos islands prohibiting the extraction of any natural resources therein
the laws of the UK, where applicable, apply
overseas territory of the UK; administered by a commissioner, resident in the Foreign and Commonwealth Office in London
white with six blue wavy horizontal stripes; the flag of the UK is in the upper hoist-side quadrant; the striped section bears a palm tree and yellow crown (the symbols of the territory) centered on the outer half of the flag; the wavy stripes represent the Indian Ocean; although not officially described, the six blue stripes may stand for the six main atolls of the archipelago
Armed Forces Radio and Television Service (AFRTS) broadcasts over 3 separate frequencies for US and UK military personnel stationed on the islands (2009)
none (overseas territory of the UK)
none (overseas territory of the UK)
the US dollar is used
All economic activity is concentrated on the largest island of Diego Garcia, where a joint UK-US military facility is located. Construction projects and various services needed to support the military installation are performed by military and contract employees from the UK, Mauritius, the Philippines, and the US. Some of the natural resources found in this territory include coconuts, fish, and sugarcane. Sugarcane is still a major export for this territory. There are no industrial or agricultural activities on the islands. The territory earns foreign exchange by selling fishing licenses and postage stamps.