The Advisory Opinion of the International Court of Justice [ICJ] on the Separation of the Chagos Archipelago from Mauritius in 1965, has been hailed as a major victory by the government of Mauritius and representatives of the Chagossians.Footnote 1 The opinion followed four decades of negotiations between the Mauritian and British governments over the future of the Archipelago, where an American defence facility was established on Diego Garcia, the largest of the islands, whose inhabitants were forcibly removed, and prevented from returning, to make way for the establishment of a new colony called the “British Indian Ocean Territory”.Footnote 2 In a virtually unanimous decision (thirteen votes to one,Footnote 3 with Judge Donoghue dissenting), the ICJ expressed its opinion that “the process of decolonization of Mauritius was not lawfully completed when that country acceded to independence in 1968, following the separation of the Chagos Archipelago”.Footnote 4 It further expressed its opinion that “the United Kingdom is under an obligation to bring to an end its administration of the Chagos Archipelago as rapidly as possible”.Footnote 5 It finally expressed the view that “all Member States are under an obligation to co-operate with the United Nations in order to complete the decolonization of Mauritius”.Footnote 6
The Advisory Opinion could have far-reaching consequences, both in terms of the status of the Archipelago, and for other long-standing territorial disputes that arose during decolonization. This is because the ICJ concluded, for the first time, that UN General Assembly Resolution 1514 (the “Decolonization Declaration”) reflected customary international law, and that it had attained this status in law some time between the years 1965 and 1968. Accordingly, it could be argued that other territorial disputes that arose as a result of the failure to complete the process of decolonization after 1965, to which the Decolonization Declaration was applicable, could bring their disputes before the ICJ in the form of Advisory Opinions.
Before considering the wider implications of the Advisory Opinion, this comment revisits the history of the establishment of the American military base on Diego Garcia. It then considers the questions formulated by the UN General Assembly for the Advisory Opinion, before considering what the Court had to say about self-determination.
I. THE ESTABLISHMENT OF THE BRITISH INDIAN OCEAN TERRITORY
The Chagos Archipelago, a group of islands located in the Indian Ocean 2,220 km north-west of Mauritius, was administered by the UK as a dependency of the Colony of Mauritius from 1814 and 1965.Footnote 7 The island of Diego Garcia—home to a US naval and air base—accounts for more than half of the archipelago's total land area of 1,950 sq km.Footnote 8
In 1946, the UK listed Mauritius as a non-self-governing territory and transmitted reports to the General Assembly under Article 73(e) of the Charter of the United Nations. Significantly, in these reports the UK referred to the Chagos Archipelago as a dependency of Mauritius.Footnote 9 It should also be mentioned, although the ICJ did not refer to this, that the inhabitants of the Chagos Archipelago were considered citizens of the UK under the British Nationality Act 1948 before the separation of the Archipelago.Footnote 10
In 1964, discussions commenced between the US and the UK regarding the use by the US of the island of Diego Garcia for the purposes of defence.Footnote 11 The US, embroiled in the Vietnam War, wanted to establish a military base in the Indian Ocean, where the UK still had a colony, having lost its other colonies in Malaya, India, Pakistan, Burma, and Ceylon.Footnote 12 They hoped that the new military facility would prevent the spread of Communist ideology to the Third World.Footnote 13
On 8 November 1965, the UK established the British Indian Ocean Territory [BIOT], a new colony, consisting of the Chagos Archipelago, detached from Mauritius, and the Adalbra, Farquhar, and Desroches islands detached from the Seychelles.Footnote 14 Between 1967 and 1973, the entire population of the Archipelago were forcibly removed and prevented from returning.Footnote 15
Prior to the independence of Mauritius on 12 March 1968, Prime Minister Seewoosagur Ramgoolam, and the Mauritian Council of Ministers, indicated their preference for a long-term lease of the islands, rather than detachment, but the UK was not willing to consider this alternative.Footnote 16 Accordingly, Sir Seewoosagur and the Council of Ministers were given no choice but to accept the separation of the Chagos Archipelago “in principle” as the price for independence.Footnote 17
II. THE UN GENERAL ASSEMBLY'S REQUEST FOR AN ADVISORY OPINION
Since independence, Mauritius has consistently claimed that the separation of the Chagos Archipelago was imposed without its consent. However, the UN General Assembly only became involved with the issue on 22 June 2017, after a four-decade hiatus, when it requested an Advisory Opinion from the ICJ. Until that movement, the dispute between Mauritius and the UK had been addressed in bilateral negotiations between the two countries.
The General Assembly resolution requesting the Advisory Opinion was adopted by ninety-four votes to fifteen, with sixty-five abstentions.Footnote 18 The questions asked of the ICJ were framed as follows:
(a) Was the process of decolonization of Mauritius lawfully completed when Mauritius was granted independence in 1968, following the separation of the Chagos Archipelago from Mauritius and having regard to international law, including obligations reflected in General Assembly resolutions 1514 (XV) of 14 December 1960, 2066 (XX) of 16 December 1965, 2232 (XXI) of 20 December 1966 and 2357 (XXII) of 19 December 1967?;
(b) What are the consequences under international law, including obligations reflected in the above-mentioned resolutions, arising from the continued administration by the United Kingdom of Great Britain and Northern Ireland of the Chagos Archipelago, including with respect to the inability of Mauritius to implement a programme for the resettlement on the Chagos Archipelago of its nationals, in particular those of Chagossian origin?.
Despite the reference to sovereignty in the first sentence of the preamble,Footnote 19 the questions were formulated to avoid the appearance that there was a sovereignty dispute between the UK and Mauritius, which had arisen in their bilateral relations following the latter's independence. This was necessary in order to avoid the argument that the Advisory Opinion was being used to circumvent the absence of British consent to the judicial settlement of the bilateral dispute. Because the UK and Mauritius had submitted declarations to the ICJ that excluded disputes with other Commonwealth states from their acceptance of the Court's compulsory jurisdiction,Footnote 20 the UK was of view that the resolution had been drafted to provide a back-door route to the Court.Footnote 21 The UK pointed out, for example, that the UN General Assembly had not adopted a single resolution on the question of Mauritius since its independence in 1968.Footnote 22
Although the UN had not been involved with the decolonization of Mauritius for many years, decolonization has remained of special concern to the UN General Assembly. For example, in 2010, the General Assembly declared the period 2011–20 the Third International Decade for the Eradication of Colonialism.Footnote 23 And of course, colonial disputes are fundamentally disputes about sovereignty; namely, the process of transferring power to the people of a non-self-governing territory.Footnote 24 But they are an exceptional type of dispute; a dispute that does not always depend on the consent of the administering power, since not all cases of decolonization were consensual.
III. THE WRITTEN AND ORAL ARGUMENTS
In addition to the African Union, written statements were filed in the Registry of the Court by the following states: Belize, Germany, Cyprus, Liechtenstein, the Netherlands, the UK, Serbia, France, Israel, the Russian Federation, the US, the Seychelles, Australia, India, Chile, Brazil, the Republic of Korea, Madagascar, the People's Republic of China, Djibouti, Mauritius, Nicaragua, Guatemala, Argentina, Lesotho, Cuba, Viet Nam, South Africa, the Marshall Islands, Namibia, and Niger.Footnote 25
Oral pleadings were made by Mauritius, the UK, South Africa, Germany, Argentina, Australia, Belize, Botswana, Brazil, Cyprus, the US, Guatemala, the Marshall Islands, India, Israel, Kenya, Nicaragua, Nigeria, Serbia, Thailand, Vanuatu, Zambia, and the African Union.Footnote 26
Of the written and oral statements, only the UK, France, Israel, the US, Australia, Chile, and Korea framed the issue as a sovereignty dispute. All the other states viewed the dispute as being concerned exclusively with self-determination. The Russian Federation took a non-committal position, viewing the issue as one of self-determination but also expressing caution that the Advisory Opinion not be used to settle bilateral disputes.Footnote 27
IV. THE ADVISORY OPINION
On 25 February, the ICJ delivered its Advisory Opinion. It made short shrift of the argument that there was a bilateral dispute between Mauritius and the UK regarding sovereignty over the Chagos Archipelago that was at the core of the advisory proceedings. The ICJ observed that the General Assembly had:
[N]ot sought the Court's opinion to resolve a territorial dispute between two States. Rather, the purpose of the request is for the General Assembly to receive the Court's assistance so that it may be guided in the discharge of its functions relating to the decolonization of Mauritius.Footnote 28
In the Court's view the opinion was requested on the matter of decolonization, which is of particular concern to the UN.Footnote 29
In answer to question (a), the Court explained that it had to first determine the relevant period of time for the purposes of identifying the applicable rules of international law before determining the content of the law.Footnote 30 After determining that the relevant period of time for identifying the applicable rules of international law was between the separation of the Archipelago in 1965 and the independence of Mauritius in 1968, the ICJ concluded that the adoption of the Decolonization Declaration by the General Assembly on 14 December 1960 was a “defining moment in the consolidation of State practice on decolonization”.Footnote 31
Although the ICJ was of the view that the Decolonization Declaration was formally a recommendation, it had a “declaratory character with regard to the right to self-determination as a customary norm, in view of its content and the conditions of its adoption”.Footnote 32 It added, “[t]he wording used in resolution 1514 (XV) has a normative character, in so far as it affirms that ‘[a]ll peoples have the right to self-determination’”.Footnote 33
The ICJ recalled that the right to self-determination applied to the entirety of a non-self-governing territory. In support of this view it referred to paragraph 6 of the Decolonization Declaration, which provided that “Any attempt aimed at the partial or total disruption of the national unity and the territorial integrity of a country is incompatible with the purposes and principles of the Charter of the United Nations”.Footnote 34 According to the ICJ:
Both State practice and opinio juris at the relevant time confirm the customary law character of the right to territorial integrity of a non-self-governing territory as a corollary of the right to self-determination. No example has been brought to the attention of the Court in which, following the adoption of resolution 1514 (XV), the General Assembly or any other organ of the United Nations has considered as lawful the detachment by the administering Power of part of a non-self-governing territory, for the purpose of maintaining it under its colonial rule. States have consistently emphasized that respect for the territorial integrity of a non-self-governing territory is a key element of the exercise of the right to self-determination under international law.Footnote 35
The peoples of non-self-governing territories are entitled to exercise their right to self-determination, the Court said, in relation to their territory as an integral, complete, unit, and the integrity of that unit must be respected by the administering power at the moment of decolonization: “[i]t follows that any detachment by the administering Power of part of a non-self-governing territory, unless based on the freely expressed and genuine will of the people of the territory concerned, is contrary to the right to self-determination.”Footnote 36
Applying the law of self-determination to the separation of the Chagos Archipelago, the ICJ concluded that “heightened scrutiny” should be given to the issue of consent when part of a non-self-governing territory is separated to create a new colony. Having studied the circumstances in which the Council of Ministers of the Colony of Mauritius agreed to the detachment of the Archipelago “in principle”, the Court considered that the detachment was “not based on the free and genuine expression of the will of the people concerned”.Footnote 37 Accordingly, the ICJ concluded in answer to question (a) that “the process of decolonization of Mauritius was not lawfully completed when Mauritius acceded to independence in 1968”.Footnote 38 Having reached this conclusion, the answer to question (b) was self-explanatory. The UK's ongoing administration of the Chagos Archipelago constituted “a wrongful act entailing the international responsibility of that State”.Footnote 39 The ICJ described that wrongful act as being of a “continuing character”.Footnote 40 Accordingly, it concluded that:
[T]he United Kingdom is under an obligation to bring an end to its administration of the Chagos Archipelago as rapidly as possible, thereby enabling Mauritius to complete the decolonization of its territory in a manner consistent with the right of peoples to self-determination.Footnote 41
The ICJ explained that it was for the General Assembly to decide on the modalities required to complete the decolonization of Mauritius, which all Member States are required to co-operate with in putting into effect, given that self-determination is an obligations erga omnes, giving these states a legal interest in protecting this right.Footnote 42
V. THE DISSENT AND SEPARATE OPINIONS AND DECLARATIONS
Of the thirteen Judges that participated in the Opinion, six issued Declarations (Vice-President Xue, Judges Tomka, Abraham, Gevorgian, Salam, and Iwasawa), four issued Separate Opinions (Judges Cançado Trindade, Gaja, Sebutinde, and Robinson), and one issued a Dissenting Opinion (Judge Donoghue). In addition, Judges Cançado Trindade and Robinson issued a Joint Declaration, in addition to their Separate Opinions.
In the sole dissent, Judge Donoghue expressed her view that the Advisory Opinion had “the effect of circumventing the absence of United Kingdom consent to judicial settlement of the bilateral dispute between the United Kingdom and Mauritius regarding sovereignty over the Chagos Archipelago and thus undermines the integrity of the Court's judicial function”.Footnote 43 In her view, the ICJ should have exercised its discretion to decline to give the opinion.
In contrast, Vice-President Xue thought that framing the issue as a sovereignty dispute between Mauritius and the UK was devoid of historical context. She explained that, when the separation of the Chagos Archipelago was being contemplated by British officials in 1964–65, they were aware that they were establishing a new colony and that this was unlikely to escape criticism in the UN. The fact that Mauritius sought to resolve its dispute bilaterally with the UK did not change anything, as decolonization issues were often considered at both the bilateral and multilateral level: “[t]hey are not mutually exclusive under international law.”Footnote 44
For some Judges, the ICJ did not go far enough in its enumeration of the law of self-determination. Judges Cançado Trindade, Robinson, and Sebutinde thought the Court could have said much more about the status of self-determination in international law, which they thought had consolidated into a peremptory norm of a jus cogens character.Footnote 45 According to Cançado Trindade it was as if “the Court remains (in 2019) haunted by the Barcelona Traction ghost of 1970 (beholding only obligations erga omnes, without jus cogens), as well by the East Timor injustice (to its people) of 1995, resulting from its strictly inter-State outlook”.Footnote 46
VI. CONCLUSION
The Advisory Opinion could have far-reaching consequences not only for the UK's position in the Indian Ocean, but for other states that have long-standing self-determination disputes to which the Decolonization Declaration is applicable.Footnote 47 However, with decolonization virtually complete, there are not that many disputes that are likely to come before the ICJ—certainly not a floodgate—and even where such disputes exist, the peoples concerned would need a state to take up their case and use its political capital to secure a majority vote in the UN General Assembly to request an Advisory Opinion.
The ICJ's opinion that self-determination had emerged as customary international law in 1965–68 could however be of assistance to a rather exceptional and long-standing dispute: that between Israel and Palestine. In this connection, it was probably no coincidence that, for the first time in over fifty years,Footnote 48 Israel took part in the oral proceedings at the ICJ on the Chagos Opinion, arguing that the ICJ should exercise its discretion to decline to give the opinion.Footnote 49 Undoubtedly, Israel's Foreign Ministry was aware of the parallels between the UK's administration of the Chagos Archipelago and Israel's occupation of East Jerusalem, the West Bank, and the Gaza Strip, which the Palestinians have long argued is unlawful.
On 28 September 2018, Palestine instituted proceedings at the ICJ challenging the Trump administration's decision to move its embassy to Jerusalem.Footnote 50 In the first phase of the case, Palestine will have to argue that it is a state, and, in this connection, it may have to argue that it has had a right to claim sovereignty over East Jerusalem, the West Bank, and the Gaza Strip since 1967, and which Israel has refused to withdraw from despite the adoption by the UN Security Council of Resolutions 242 (1967) and 338 (1973).Footnote 51 In this regard, the ICJ's conclusion in the Chagos Advisory Opinion that “the United Kingdom's continued administration of the Chagos Archipelago constitutes a wrongful act entailing the international responsibility of that State” could be cited to argue that Israel's continued administration of the territories it occupied on 4 June 1967 constitutes a wrongful act entailing the responsibility of that state. In his Declaration, Judge Gevorgian observed that, in the ICJ's Advisory Opinion in Wall, the Court “was able to rely on the United Nations Security Council's determination that the occupation of Palestinian territory was illegal, notably in resolution 242 (1967)”.Footnote 52 Gevorgian mentioned the Wall opinion to distinguish the Chagos Opinion from the Namibia and Wall Advisory Opinions, where the Security Council had clearly expressed its view that the retention of those territories by South Africa and Israel was contrary to international law.
Intriguingly, the ICJ did not mention how the Decolonization Declaration came to reflect customary international law, other than to describe it as a “defining moment” in the consolidation of state practice on decolonization. Nor did the ICJ mention how that Declaration jettisoned an older tradition of self-government. Only Judge Gaja made the observation that:
Under Article 73 of the Charter of the United Nations, an administering Power of a non-self-governing territory had to promote the well-being of the inhabitants and their self-government. Establishing a new colony (the British Indian Ocean Territory) in order to construct a military base on the Archipelago and expelling the indigenous population were not steps in that direction and could not be regarded as a form of decolonization consistent with the obligations flowing from the Charter.Footnote 53
In paragraph 156 of the Advisory Opinion, the ICJ cited General Assembly Resolution 1541, which it claimed expressed the means of “implementing self-determination”. Yet the word “self-determination” does not appear in Resolution 1541.Footnote 54 That resolution uses the word “self-government”.Footnote 55
The omission of the South West Africa Cases (1960–66) from the Opinion, and from the submissions to the ICJ, was also glaring, given that self-determination was raised by the Applicants in the merits of the South West Africa Cases, which covered a similar time period.Footnote 56 It will be recalled that Ethiopia and Liberia chose not to invoke the Decolonization Declaration in their argument on the merits, even in support of their argument that territorial apartheid was contrary to international law.Footnote 57 The UK could have argued that the omission of the Decolonization Declaration from the Applicant's memorial on the merits of the South West Africa Cases provided evidence that, in the view of the Applicants themselves, the Decolonization Declaration did not reflect customary international law in the 1960s. Why the UK did not cite the Applicant's memorial in the South West Africa Cases to support its view that the Decolonization Declaration did not reflect customary international law by 1965, when the Chagos was detached from Mauritius, remains a mystery.
Finally, the ICJ was careful to say that the wording used in the Decolonization Declaration had a normative character, only insofar as it affirmed that “[a]ll peoples have the right to self-determination”.Footnote 58 The Court did not go so far as to say that the Decolonization Declaration as a whole reflected customary international law. It did, however, concede that state practice and opinio juris confirmed the customary law character of the right to territorial integrity of a non-self-governing territory as a corollary of the right to self-determination.Footnote 59
The only conclusion to be drawn from the Advisory Opinion is that the UK has been administering the Archipelago in violation of international law for over four decades, and that Mauritius has had sovereignty over the Archipelago since 1965, which the UK has been illegally administering. Regarding the future of the military facilities on Diego Garcia, Mauritius has assured the UK and the US governments that the exercise of effective control by Mauritius over the Chagos Archipelago would not in any way pose any threat to the military base: “Mauritius is committed to the continued operation of the base in Diego Garcia under a long-term framework, which Mauritius stands ready to enter into with the concerned parties.”Footnote 60
%20-%20https://sketch.com%20--%3e%3ctitle%3e3ECBBF50-FD08-412A-943D-2CFC5E025A16%3c/title%3e%3cdesc%3eCreated%20with%20sketchtool.%3c/desc%3e%3cg%20id='Stylesheet'%20stroke='none'%20stroke-width='1'%20fill='none'%20fill-rule='evenodd'%3e%3cg%20transform='translate(-926.000000,%20-668.000000)'%20id='BUTTONS'%3e%3cg%20transform='translate(100.000000,%20597.000000)'%3e%3cg%20id='BTN-/-RIGHTS'%20transform='translate(816.000000,%2065.000000)'%3e%3cg%20id='ICON-/-Rights'%20transform='translate(10.000000,%206.000000)'%3e%3cpath%20d='M13.5752841,0%20L1.34943182,0%20C0.59375,0%200,0.586666667%200,1.33333333%20L0,22.6666667%20C0,23.4133333%200.620738636,24%201.34943182,24%20L17.6505682,24%20C18.40625,24%2019,23.3866667%2019,22.6666667%20L19,5.36%20L13.5752841,0%20Z%20M13.5752841,1.89333333%20L17.0838068,5.36%20L13.5752841,5.36%20L13.5752841,1.89333333%20Z%20M1.34943182,22.6666667%20L1.34943182,1.33333333%20L12.1988636,1.33333333%20L12.1988636,5.36%20C12.1988636,6.10666667%2012.7926136,6.69333333%2013.5482955,6.69333333%20L17.6235795,6.69333333%20L17.6505682,22.6666667%20L1.34943182,22.6666667%20Z'%20id='Shape'%20fill='%23595959'%20fill-rule='nonzero'%3e%3c/path%3e%3ccircle%20id='Oval'%20stroke='%23595959'%20stroke-width='1.5'%20fill='%23595959'%20cx='9.5'%20cy='13.5355339'%20r='5.5'%3e%3c/circle%3e%3cpolyline%20id='Path-2'%20stroke='%23FFFFFF'%20stroke-width='1.5'%20transform='translate(9.500000,%2013.035534)%20rotate(45.000000)%20translate(-9.500000,%20-13.035534)%20'%20points='8%2016.0355339%2011%2016.0355339%2011%2010.0355339'%3e%3c/polyline%3e%3c/g%3e%3c/g%3e%3c/g%3e%3c/g%3e%3c/g%3e%3c/svg%3e)
The Advisory Opinion of the International Court of Justice [ICJ] on the Separation of the Chagos Archipelago from Mauritius in 1965, has been hailed as a major victory by the government of Mauritius and representatives of the Chagossians.Footnote 1 The opinion followed four decades of negotiations between the Mauritian and British governments over the future of the Archipelago, where an American defence facility was established on Diego Garcia, the largest of the islands, whose inhabitants were forcibly removed, and prevented from returning, to make way for the establishment of a new colony called the “British Indian Ocean Territory”.Footnote 2 In a virtually unanimous decision (thirteen votes to one,Footnote 3 with Judge Donoghue dissenting), the ICJ expressed its opinion that “the process of decolonization of Mauritius was not lawfully completed when that country acceded to independence in 1968, following the separation of the Chagos Archipelago”.Footnote 4 It further expressed its opinion that “the United Kingdom is under an obligation to bring to an end its administration of the Chagos Archipelago as rapidly as possible”.Footnote 5 It finally expressed the view that “all Member States are under an obligation to co-operate with the United Nations in order to complete the decolonization of Mauritius”.Footnote 6
The Advisory Opinion could have far-reaching consequences, both in terms of the status of the Archipelago, and for other long-standing territorial disputes that arose during decolonization. This is because the ICJ concluded, for the first time, that UN General Assembly Resolution 1514 (the “Decolonization Declaration”) reflected customary international law, and that it had attained this status in law some time between the years 1965 and 1968. Accordingly, it could be argued that other territorial disputes that arose as a result of the failure to complete the process of decolonization after 1965, to which the Decolonization Declaration was applicable, could bring their disputes before the ICJ in the form of Advisory Opinions.
Before considering the wider implications of the Advisory Opinion, this comment revisits the history of the establishment of the American military base on Diego Garcia. It then considers the questions formulated by the UN General Assembly for the Advisory Opinion, before considering what the Court had to say about self-determination.
I. THE ESTABLISHMENT OF THE BRITISH INDIAN OCEAN TERRITORY
The Chagos Archipelago, a group of islands located in the Indian Ocean 2,220 km north-west of Mauritius, was administered by the UK as a dependency of the Colony of Mauritius from 1814 and 1965.Footnote 7 The island of Diego Garcia—home to a US naval and air base—accounts for more than half of the archipelago's total land area of 1,950 sq km.Footnote 8
In 1946, the UK listed Mauritius as a non-self-governing territory and transmitted reports to the General Assembly under Article 73(e) of the Charter of the United Nations. Significantly, in these reports the UK referred to the Chagos Archipelago as a dependency of Mauritius.Footnote 9 It should also be mentioned, although the ICJ did not refer to this, that the inhabitants of the Chagos Archipelago were considered citizens of the UK under the British Nationality Act 1948 before the separation of the Archipelago.Footnote 10
In 1964, discussions commenced between the US and the UK regarding the use by the US of the island of Diego Garcia for the purposes of defence.Footnote 11 The US, embroiled in the Vietnam War, wanted to establish a military base in the Indian Ocean, where the UK still had a colony, having lost its other colonies in Malaya, India, Pakistan, Burma, and Ceylon.Footnote 12 They hoped that the new military facility would prevent the spread of Communist ideology to the Third World.Footnote 13
On 8 November 1965, the UK established the British Indian Ocean Territory [BIOT], a new colony, consisting of the Chagos Archipelago, detached from Mauritius, and the Adalbra, Farquhar, and Desroches islands detached from the Seychelles.Footnote 14 Between 1967 and 1973, the entire population of the Archipelago were forcibly removed and prevented from returning.Footnote 15
Prior to the independence of Mauritius on 12 March 1968, Prime Minister Seewoosagur Ramgoolam, and the Mauritian Council of Ministers, indicated their preference for a long-term lease of the islands, rather than detachment, but the UK was not willing to consider this alternative.Footnote 16 Accordingly, Sir Seewoosagur and the Council of Ministers were given no choice but to accept the separation of the Chagos Archipelago “in principle” as the price for independence.Footnote 17
II. THE UN GENERAL ASSEMBLY'S REQUEST FOR AN ADVISORY OPINION
Since independence, Mauritius has consistently claimed that the separation of the Chagos Archipelago was imposed without its consent. However, the UN General Assembly only became involved with the issue on 22 June 2017, after a four-decade hiatus, when it requested an Advisory Opinion from the ICJ. Until that movement, the dispute between Mauritius and the UK had been addressed in bilateral negotiations between the two countries.
The General Assembly resolution requesting the Advisory Opinion was adopted by ninety-four votes to fifteen, with sixty-five abstentions.Footnote 18 The questions asked of the ICJ were framed as follows:
(a) Was the process of decolonization of Mauritius lawfully completed when Mauritius was granted independence in 1968, following the separation of the Chagos Archipelago from Mauritius and having regard to international law, including obligations reflected in General Assembly resolutions 1514 (XV) of 14 December 1960, 2066 (XX) of 16 December 1965, 2232 (XXI) of 20 December 1966 and 2357 (XXII) of 19 December 1967?;
(b) What are the consequences under international law, including obligations reflected in the above-mentioned resolutions, arising from the continued administration by the United Kingdom of Great Britain and Northern Ireland of the Chagos Archipelago, including with respect to the inability of Mauritius to implement a programme for the resettlement on the Chagos Archipelago of its nationals, in particular those of Chagossian origin?.
Despite the reference to sovereignty in the first sentence of the preamble,Footnote 19 the questions were formulated to avoid the appearance that there was a sovereignty dispute between the UK and Mauritius, which had arisen in their bilateral relations following the latter's independence. This was necessary in order to avoid the argument that the Advisory Opinion was being used to circumvent the absence of British consent to the judicial settlement of the bilateral dispute. Because the UK and Mauritius had submitted declarations to the ICJ that excluded disputes with other Commonwealth states from their acceptance of the Court's compulsory jurisdiction,Footnote 20 the UK was of view that the resolution had been drafted to provide a back-door route to the Court.Footnote 21 The UK pointed out, for example, that the UN General Assembly had not adopted a single resolution on the question of Mauritius since its independence in 1968.Footnote 22
Although the UN had not been involved with the decolonization of Mauritius for many years, decolonization has remained of special concern to the UN General Assembly. For example, in 2010, the General Assembly declared the period 2011–20 the Third International Decade for the Eradication of Colonialism.Footnote 23 And of course, colonial disputes are fundamentally disputes about sovereignty; namely, the process of transferring power to the people of a non-self-governing territory.Footnote 24 But they are an exceptional type of dispute; a dispute that does not always depend on the consent of the administering power, since not all cases of decolonization were consensual.
III. THE WRITTEN AND ORAL ARGUMENTS
In addition to the African Union, written statements were filed in the Registry of the Court by the following states: Belize, Germany, Cyprus, Liechtenstein, the Netherlands, the UK, Serbia, France, Israel, the Russian Federation, the US, the Seychelles, Australia, India, Chile, Brazil, the Republic of Korea, Madagascar, the People's Republic of China, Djibouti, Mauritius, Nicaragua, Guatemala, Argentina, Lesotho, Cuba, Viet Nam, South Africa, the Marshall Islands, Namibia, and Niger.Footnote 25
Oral pleadings were made by Mauritius, the UK, South Africa, Germany, Argentina, Australia, Belize, Botswana, Brazil, Cyprus, the US, Guatemala, the Marshall Islands, India, Israel, Kenya, Nicaragua, Nigeria, Serbia, Thailand, Vanuatu, Zambia, and the African Union.Footnote 26
Of the written and oral statements, only the UK, France, Israel, the US, Australia, Chile, and Korea framed the issue as a sovereignty dispute. All the other states viewed the dispute as being concerned exclusively with self-determination. The Russian Federation took a non-committal position, viewing the issue as one of self-determination but also expressing caution that the Advisory Opinion not be used to settle bilateral disputes.Footnote 27
IV. THE ADVISORY OPINION
On 25 February, the ICJ delivered its Advisory Opinion. It made short shrift of the argument that there was a bilateral dispute between Mauritius and the UK regarding sovereignty over the Chagos Archipelago that was at the core of the advisory proceedings. The ICJ observed that the General Assembly had:
[N]ot sought the Court's opinion to resolve a territorial dispute between two States. Rather, the purpose of the request is for the General Assembly to receive the Court's assistance so that it may be guided in the discharge of its functions relating to the decolonization of Mauritius.Footnote 28
In the Court's view the opinion was requested on the matter of decolonization, which is of particular concern to the UN.Footnote 29
In answer to question (a), the Court explained that it had to first determine the relevant period of time for the purposes of identifying the applicable rules of international law before determining the content of the law.Footnote 30 After determining that the relevant period of time for identifying the applicable rules of international law was between the separation of the Archipelago in 1965 and the independence of Mauritius in 1968, the ICJ concluded that the adoption of the Decolonization Declaration by the General Assembly on 14 December 1960 was a “defining moment in the consolidation of State practice on decolonization”.Footnote 31
Although the ICJ was of the view that the Decolonization Declaration was formally a recommendation, it had a “declaratory character with regard to the right to self-determination as a customary norm, in view of its content and the conditions of its adoption”.Footnote 32 It added, “[t]he wording used in resolution 1514 (XV) has a normative character, in so far as it affirms that ‘[a]ll peoples have the right to self-determination’”.Footnote 33
The ICJ recalled that the right to self-determination applied to the entirety of a non-self-governing territory. In support of this view it referred to paragraph 6 of the Decolonization Declaration, which provided that “Any attempt aimed at the partial or total disruption of the national unity and the territorial integrity of a country is incompatible with the purposes and principles of the Charter of the United Nations”.Footnote 34 According to the ICJ:
Both State practice and opinio juris at the relevant time confirm the customary law character of the right to territorial integrity of a non-self-governing territory as a corollary of the right to self-determination. No example has been brought to the attention of the Court in which, following the adoption of resolution 1514 (XV), the General Assembly or any other organ of the United Nations has considered as lawful the detachment by the administering Power of part of a non-self-governing territory, for the purpose of maintaining it under its colonial rule. States have consistently emphasized that respect for the territorial integrity of a non-self-governing territory is a key element of the exercise of the right to self-determination under international law.Footnote 35
The peoples of non-self-governing territories are entitled to exercise their right to self-determination, the Court said, in relation to their territory as an integral, complete, unit, and the integrity of that unit must be respected by the administering power at the moment of decolonization: “[i]t follows that any detachment by the administering Power of part of a non-self-governing territory, unless based on the freely expressed and genuine will of the people of the territory concerned, is contrary to the right to self-determination.”Footnote 36
Applying the law of self-determination to the separation of the Chagos Archipelago, the ICJ concluded that “heightened scrutiny” should be given to the issue of consent when part of a non-self-governing territory is separated to create a new colony. Having studied the circumstances in which the Council of Ministers of the Colony of Mauritius agreed to the detachment of the Archipelago “in principle”, the Court considered that the detachment was “not based on the free and genuine expression of the will of the people concerned”.Footnote 37 Accordingly, the ICJ concluded in answer to question (a) that “the process of decolonization of Mauritius was not lawfully completed when Mauritius acceded to independence in 1968”.Footnote 38 Having reached this conclusion, the answer to question (b) was self-explanatory. The UK's ongoing administration of the Chagos Archipelago constituted “a wrongful act entailing the international responsibility of that State”.Footnote 39 The ICJ described that wrongful act as being of a “continuing character”.Footnote 40 Accordingly, it concluded that:
[T]he United Kingdom is under an obligation to bring an end to its administration of the Chagos Archipelago as rapidly as possible, thereby enabling Mauritius to complete the decolonization of its territory in a manner consistent with the right of peoples to self-determination.Footnote 41
The ICJ explained that it was for the General Assembly to decide on the modalities required to complete the decolonization of Mauritius, which all Member States are required to co-operate with in putting into effect, given that self-determination is an obligations erga omnes, giving these states a legal interest in protecting this right.Footnote 42
V. THE DISSENT AND SEPARATE OPINIONS AND DECLARATIONS
Of the thirteen Judges that participated in the Opinion, six issued Declarations (Vice-President Xue, Judges Tomka, Abraham, Gevorgian, Salam, and Iwasawa), four issued Separate Opinions (Judges Cançado Trindade, Gaja, Sebutinde, and Robinson), and one issued a Dissenting Opinion (Judge Donoghue). In addition, Judges Cançado Trindade and Robinson issued a Joint Declaration, in addition to their Separate Opinions.
In the sole dissent, Judge Donoghue expressed her view that the Advisory Opinion had “the effect of circumventing the absence of United Kingdom consent to judicial settlement of the bilateral dispute between the United Kingdom and Mauritius regarding sovereignty over the Chagos Archipelago and thus undermines the integrity of the Court's judicial function”.Footnote 43 In her view, the ICJ should have exercised its discretion to decline to give the opinion.
In contrast, Vice-President Xue thought that framing the issue as a sovereignty dispute between Mauritius and the UK was devoid of historical context. She explained that, when the separation of the Chagos Archipelago was being contemplated by British officials in 1964–65, they were aware that they were establishing a new colony and that this was unlikely to escape criticism in the UN. The fact that Mauritius sought to resolve its dispute bilaterally with the UK did not change anything, as decolonization issues were often considered at both the bilateral and multilateral level: “[t]hey are not mutually exclusive under international law.”Footnote 44
For some Judges, the ICJ did not go far enough in its enumeration of the law of self-determination. Judges Cançado Trindade, Robinson, and Sebutinde thought the Court could have said much more about the status of self-determination in international law, which they thought had consolidated into a peremptory norm of a jus cogens character.Footnote 45 According to Cançado Trindade it was as if “the Court remains (in 2019) haunted by the Barcelona Traction ghost of 1970 (beholding only obligations erga omnes, without jus cogens), as well by the East Timor injustice (to its people) of 1995, resulting from its strictly inter-State outlook”.Footnote 46
VI. CONCLUSION
The Advisory Opinion could have far-reaching consequences not only for the UK's position in the Indian Ocean, but for other states that have long-standing self-determination disputes to which the Decolonization Declaration is applicable.Footnote 47 However, with decolonization virtually complete, there are not that many disputes that are likely to come before the ICJ—certainly not a floodgate—and even where such disputes exist, the peoples concerned would need a state to take up their case and use its political capital to secure a majority vote in the UN General Assembly to request an Advisory Opinion.
The ICJ's opinion that self-determination had emerged as customary international law in 1965–68 could however be of assistance to a rather exceptional and long-standing dispute: that between Israel and Palestine. In this connection, it was probably no coincidence that, for the first time in over fifty years,Footnote 48 Israel took part in the oral proceedings at the ICJ on the Chagos Opinion, arguing that the ICJ should exercise its discretion to decline to give the opinion.Footnote 49 Undoubtedly, Israel's Foreign Ministry was aware of the parallels between the UK's administration of the Chagos Archipelago and Israel's occupation of East Jerusalem, the West Bank, and the Gaza Strip, which the Palestinians have long argued is unlawful.
On 28 September 2018, Palestine instituted proceedings at the ICJ challenging the Trump administration's decision to move its embassy to Jerusalem.Footnote 50 In the first phase of the case, Palestine will have to argue that it is a state, and, in this connection, it may have to argue that it has had a right to claim sovereignty over East Jerusalem, the West Bank, and the Gaza Strip since 1967, and which Israel has refused to withdraw from despite the adoption by the UN Security Council of Resolutions 242 (1967) and 338 (1973).Footnote 51 In this regard, the ICJ's conclusion in the Chagos Advisory Opinion that “the United Kingdom's continued administration of the Chagos Archipelago constitutes a wrongful act entailing the international responsibility of that State” could be cited to argue that Israel's continued administration of the territories it occupied on 4 June 1967 constitutes a wrongful act entailing the responsibility of that state. In his Declaration, Judge Gevorgian observed that, in the ICJ's Advisory Opinion in Wall, the Court “was able to rely on the United Nations Security Council's determination that the occupation of Palestinian territory was illegal, notably in resolution 242 (1967)”.Footnote 52 Gevorgian mentioned the Wall opinion to distinguish the Chagos Opinion from the Namibia and Wall Advisory Opinions, where the Security Council had clearly expressed its view that the retention of those territories by South Africa and Israel was contrary to international law.
Intriguingly, the ICJ did not mention how the Decolonization Declaration came to reflect customary international law, other than to describe it as a “defining moment” in the consolidation of state practice on decolonization. Nor did the ICJ mention how that Declaration jettisoned an older tradition of self-government. Only Judge Gaja made the observation that:
Under Article 73 of the Charter of the United Nations, an administering Power of a non-self-governing territory had to promote the well-being of the inhabitants and their self-government. Establishing a new colony (the British Indian Ocean Territory) in order to construct a military base on the Archipelago and expelling the indigenous population were not steps in that direction and could not be regarded as a form of decolonization consistent with the obligations flowing from the Charter.Footnote 53
In paragraph 156 of the Advisory Opinion, the ICJ cited General Assembly Resolution 1541, which it claimed expressed the means of “implementing self-determination”. Yet the word “self-determination” does not appear in Resolution 1541.Footnote 54 That resolution uses the word “self-government”.Footnote 55
The omission of the South West Africa Cases (1960–66) from the Opinion, and from the submissions to the ICJ, was also glaring, given that self-determination was raised by the Applicants in the merits of the South West Africa Cases, which covered a similar time period.Footnote 56 It will be recalled that Ethiopia and Liberia chose not to invoke the Decolonization Declaration in their argument on the merits, even in support of their argument that territorial apartheid was contrary to international law.Footnote 57 The UK could have argued that the omission of the Decolonization Declaration from the Applicant's memorial on the merits of the South West Africa Cases provided evidence that, in the view of the Applicants themselves, the Decolonization Declaration did not reflect customary international law in the 1960s. Why the UK did not cite the Applicant's memorial in the South West Africa Cases to support its view that the Decolonization Declaration did not reflect customary international law by 1965, when the Chagos was detached from Mauritius, remains a mystery.
Finally, the ICJ was careful to say that the wording used in the Decolonization Declaration had a normative character, only insofar as it affirmed that “[a]ll peoples have the right to self-determination”.Footnote 58 The Court did not go so far as to say that the Decolonization Declaration as a whole reflected customary international law. It did, however, concede that state practice and opinio juris confirmed the customary law character of the right to territorial integrity of a non-self-governing territory as a corollary of the right to self-determination.Footnote 59
The only conclusion to be drawn from the Advisory Opinion is that the UK has been administering the Archipelago in violation of international law for over four decades, and that Mauritius has had sovereignty over the Archipelago since 1965, which the UK has been illegally administering. Regarding the future of the military facilities on Diego Garcia, Mauritius has assured the UK and the US governments that the exercise of effective control by Mauritius over the Chagos Archipelago would not in any way pose any threat to the military base: “Mauritius is committed to the continued operation of the base in Diego Garcia under a long-term framework, which Mauritius stands ready to enter into with the concerned parties.”Footnote 60