Published daily by the Lowy Institute

Maldives embroiled in Mauritius‑UK tussle over Chagos

A seemingly tranquil archipelago in the central Indian Ocean has wide-ranging strategic significance for key players.

In July 2010, Maldives submitted its claims to the United Nations for an extended Continental Shelf (Alexander Brown/Flickr)
In July 2010, Maldives submitted its claims to the United Nations for an extended Continental Shelf (Alexander Brown/Flickr)
Published 8 Dec 2021 

For decades, Mauritius and the United Kingdom have been in a dispute over ownership of the Chagos Islands in the central Indian Ocean. Recently, Maldives has become entangled in “lawfare” between the two countries over their claims to the archipelago. Maldives is the northern neighbour of Chagos, with overlapping exclusive economic zones (EEZs) that need to be demarcated. But uncertainties about which country Maldives should be negotiating with have left it in a difficult position. Any deal it makes may force it into recognising Mauritian sovereignty over the islands.

The Chagos were controversially excised from Mauritian administration just before being granted independence in 1968. The islands have no permanent population, but host a key US military base at Diego Garcia. This means that how the dispute is resolved has important strategic consequences for the Indian Ocean.

Maldives argued that Chagos was a unique case because it does not possess a population dependent on fishing, or indeed any permanent population at all.

For Maldives it’s mostly about access to fish – a matter of considerable importance due to the country’s heavy reliance on tuna for food and exports. For the owners of the Chagos (either the United Kingdom or Mauritius), the issue is over who has the power to negotiate its maritime boundaries. However, Maldives’ inconsistent approach to the dispute over the last 30 years has done it no favours.

It looked like the disagreement could be easily resolved back in 1992, when representatives from Maldives and the United Kingdom agreed to delimit their overlapping EEZs on the basis of equidistance from mutually agreed baselines. The negotiations concluded with the British providing a draft agreement with agreed terms, attaching a list of delimiting coordinates. Both sides agreed to consult with their respective governments before signing it, particularly since Maldives was in the process of drafting a new maritime law.

It took until 1996 for Maldives to pass its Maritime Zones Act, but even then it did not move to finalise the 1992 understanding. The British government went ahead anyway and published charts reflecting the agreed delimitation coordinates, which most navigational maps of the region now reflect. In April 2010, the United Kingdom declared the maritime zones around the archipelago a marine sanctuary (but not technically an EEZ).

The Chagos Islands have no permanent population, but host a key US military base at Diego Garcia (MCS Nathan Carpenter/US Pacific Fleet/Flickr)

In July 2010, Maldives submitted its claims to the United Nations for an extended continental shelf and new coordinates that claimed the full 200 nautical mile EEZ measured from Addu Atoll, the southern-most atoll in the country. This ignored the 1992 understanding with the United Kingdom and was also inconsistent with Maldives’ previous willingness to negotiate overlapping EEZs with Sri Lanka and India, its northern neighbours. Maldives argued that Chagos was a unique case because it does not possess a population dependent on fishing, or indeed any permanent population at all – an argument apparently not supported by the UN Convention on the Law of the Sea (UNCLOS), which allows EEZs to be claimed for any habitable island whether or not it is inhabited.

Mauritius then entered the fray, protesting against both the United Kingdom and Maldives. Maldives did not officially take any position over Chagos sovereignty and had previously declined to negotiate with Mauritius over maritime boundaries. However, in 2011, President of Maldives Mohamed Nasheed, during a visit to Mauritius, issued a joint communiqué stating that the two countries would make a “collective stand” against the United Kingdom in relation to their extended continental shelves and EEZs.

But when Maldives failed to implement this apparent new understanding, Mauritius initiated legal proceedings against both Maldives and the United Kingdom. Its action against the United Kingdom resulted in the International Court of Justice (ICJ) issuing an advisory opinion in 2019 that the decolonisation of Mauritius from the United Kingdom had not been lawfully completed and that the United Kingdom should end its administration of the islands as soon as possible (which the United Kingdom has effectively ignored).

Despite its 2011 joint communiqué, Maldives still does not officially recognise Mauritius’ claim to negotiate on behalf of Chagos.

Mauritius also brought an action against Maldives before the International Tribunal for the Law of the Sea (ITLOS), including expanded claims of Chagos’ EEZ measured from new baselines. This was to Maldives’ distinct disadvantage, creating even greater overlap of their EEZs of some 96,000 square kilometres. In January 2021, ITLOS rejected Maldives’ argument that the tribunal had no power to hear claims involving disputed sovereignty over Chagos. The Special Chamber of the tribunal also accepted Mauritius’ claim that the ICJ had already determined the archipelago was an integral part of Mauritius. The substance of the case is yet to be decided upon.

What’s next for Maldives? Despite its 2011 joint communiqué, Maldives still does not officially recognise Mauritius’ claim to negotiate on behalf of Chagos. Indeed it may well prefer the status quo where the Chagos is effectively a marine reserve in which fish can die of old age. Mauritius, which licenses foreign companies to fish its EEZ, might not be such a benign landlord. In 2017 and 2019, through different political administrations, Maldives was one of a handful of countries that voted in the UN against Mauritius’ claims to Chagos.

This inconsistency and failure to act in a timely way has resulted in Maldives becoming tangled in the legal action between Mauritius and the United Kingdom. In these matters, its options are not great. It could proceed with the arbitration with Mauritius, which involves cost and uncertainty. Or it could negotiate with Mauritius, at the price of recognising Mauritius’ sovereignty. A third option is to return to the 1992 understanding with the United Kingdom, which would satisfy the United Kingdom, but not Mauritius.

Whichever option it chooses, Maldives’ mixed signals and ambiguous actions since 1992 – over disputed EEZs in the Chagos Islands, Mauritius’ sovereignty over the archipelago, and fears of losing traditional fishing grounds – mean that the outcomes it least desires may eventuate anyway.


The views expressed by Ahmed Mujuthaba do not reflect the views of the Maldives National Defence Force or the Government of Maldives. David Brewster recently returned from a lengthy assignment in Maldives with funding from the Australian Department of Foreign Affairs and Trade.




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