Abstract
This essay will focus on the way in which the Lancaster House Undertakings were harnessed in support of the Chagos Tribunal’s finding that the BIOT Marine Protection Area was created in violation of international law. In particular, it will examine the way that the Tribunal applied the principle of estoppel as a means of upholding the Undertakings as though, together, they amounted to something akin to a binding international agreement. The essay will argue that such an approach fails to take into account the extent to which this principle is grounded in the recognition afforded to informal modes of behaviour. To this end, it will assert that estoppel is established by recourse to the way in which the parties to a dispute respond to a representation made by, or attributed to, the Respondent State: its operation is determined by interpreting their subsequent conduct, when viewed from the Applicant State’s perspective (subject to the test of reasonableness) rather than by relying on the parties’ shared understandings, or the Respondent State’s subjective intentions. Against this background, the essay will use the Chagos Award to demonstrate the extent to which estoppel’s normative authority is derived from an independent source of international legal obligation and the degree to which the principle’s essential character continues to be misunderstood by international courts and tribunals, notwithstanding the contribution that the Chagos Award has made to the slow evolution of this under-appreciated international legal principle.
Stephen Allen: Department of Law, Queen Mary, University of London.
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Notes
- 1.
See Chagos Marine Protected Area (Mauritius v. United Kingdom) Final Award, 18 March 2015 (available on the website of the Permanent Court of Arbitration <www.pca-cpa.org> accessed 19 August 2017), [77].
- 2.
ibid [418].
- 3.
ibid [417].
- 4.
ibid [534], [535], and [536].
- 5.
In Allen (2014), I argued that the 1965 Agreement was an unmediated treaty as a matter of international law. This argument is not pursued in this essay.
- 6.
Paragraph 22 of Final record. Cited in the Chagos Award (n 1) [77].
- 7.
ibid [78].
- 8.
ibid.
- 9.
Mauritian Legislative Assembly, ‘Report of the Select Committee on the Excision of the Chagos Archipelago (No 2 of 1983)’ (Port Louis, Mauritius, Mauritian Legislative Assembly, 1983) (The ‘Excision Report’), Appendix N, 61.
- 10.
Chagos Award (n 1) [418].
- 11.
4 November 1965. See the Excision Report (n 9), Appendix M, 59–60.
- 12.
ibid 59–60.
- 13.
ibid. Appendices O and P, 62–63.
- 14.
Chagos Award (n 1) [79].
- 15.
ibid [82].
- 16.
Excision Report (n 9) Appendix R, 65.
- 17.
SI 1965/1920.The Sovereign in Council had the authority to make such an Order by virtue of the Colonial Boundaries Act 1895.
- 18.
See Allen (2014).
- 19.
See the Excision Report (n 9).
- 20.
ibid [36]. Paragraph 5 of the Colonial Declaration, UN General Assembly Resolution 1514(XV)(1960), condemns the imposition of conditions and/or reservations regarding the achievement of independence and paragraph 6 decries the dismemberment of a territorial integrity of colonial units in advance of independence.
- 21.
On the basis of Mauritius’ fourth submission—that the BIOT MPA was incompatible with the substantive and procedural obligations set out in the Law of the Sea Convention. Chagos Award (n 1) [323].
- 22.
ibid [418].
- 23.
ibid [421–422]. Here the Tribunal adopted Mauritius’ argument in this respect.
- 24.
ibid [391] and [393].
- 25.
ibid [394] and [397].
- 26.
ibid [391] and [400].
- 27.
ibid [424].
- 28.
Hendry and Dickson (2011), p. 261. Chagos Award ibid.
- 29.
For example, the Declaration on the Principles of International Law concerning Friendly Relations and Co-operation Among States recognised that the people of a Non-Self-Governing Territory have a separate status that is distinct from that Territory’s the metropolitan colonial power which administers it. UN General Assembly Resolution 2625(XXV)(1970). This argument is developed in Allen (2014), chapters 5 and 6.
- 30.
The Chagos Tribunal attached considerable significance to the UK government’s instructions to the British Governor to secure the detachment on the ‘conditions’ negotiated at the Lancaster House Conference. See Award (n 1) [423]. However, it is hard to surmise from this statement that this term is indicative of the creation of an instrument giving rise to legal rights and obligations.
- 31.
ibid [424].
- 32.
ibid [425].
- 33.
ibid [424].
- 34.
ibid [423].
- 35.
ibid [425].
- 36.
ibid [427].
- 37.
ibid [426]. In support of this approach the Tribunal invoked the ICJ’s decision in the Aegean Continental Shelf Case (Greece/Turkey) (1978) ICJ Reps 3, [96]. Mauritius was not a State at the time the 1965 Agreement was concluded.
- 38.
Chagos Award ibid [427].
- 39.
ibid [425].
- 40.
ibid [428].
- 41.
See Allen (2014), chapter 3.
- 42.
Certain German Interests in Polish Upper Silesia Case, (1926) PCIJ, Series A, No. 7, 19.
- 43.
Shaw (1996), pp. 75 and 97.
- 44.
Frontier Dispute (Burkina Faso/Mali) Case (1992) ICJ Reps 554, 566, [23].
- 45.
ibid 568, [30].
- 46.
Berman and Bentley (2016).
- 47.
Article 2(a) of the Vienna Convention on the Law of Treaties (1969) 1155 UNTS 331 provides that: ‘“treaty” means an international agreement concluded between States in written form and governed by international law, whether embodied in a single instrument or in two or more related instruments and whatever its particular designation’.
- 48.
- 49.
Hillgenberg believes that the creation of international legal rights and obligations through international agreements is a matter of choice; consequently, he endorses the existence of a clear division between treaties and non-treaty agreements by reference to the intentions of the parties. Ibid., 502–503. However, it is clear that this argument has limited resonance in the present context: Mauritius had no meaningful choice with regard to the decision to conclude the 1965 Agreement. Moreover, it had very little influence concerning the form and character of the Agreement. And, in any event, Mauritius had not acceded to independence at time the Agreement was entered into and, as such, it did not enjoy full international legal personality—it was not a State—at the material time.
- 50.
Satow’s Diplomatic Practice (n 47) [33.21].
- 51.
ibid.
- 52.
- 53.
Although such a conclusion attaches no weight to the political dynamics that informed this arrangement concluded between a colonial power and one of its Non-Self-Governing Territories. See Allen (2014).
- 54.
- 55.
In a meeting, held on 20 September 1965, between the British Prime Minister and the Mauritian Premier, Ramgoolam suggested that the best way forward would be for the UK government to grant Mauritius its independence and then allow it to negotiate directly with the US and UK governments regarding the detachment of the Chagos Islands from Mauritius. TNA PRO 20 September 1965, Letter and Note for the Record from JO Wright, Prime Minister’s Office to JW Stacpoole, Colonial Office. TNA PRO 20 September 1965, Record of a conversation between the Prime Minister and the Premier of Mauritius, at Downing Street, FO 371/184528 Z4/172. See Allen (2014), chapter 3.
- 56.
See Allen (2014).
- 57.
Chagos Award (n 1) [428].
- 58.
ibid.
- 59.
ibid [434].
- 60.
ibid [435].
- 61.
ibid, [438].
- 62.
- 63.
Chagos Award (n 1) [437].
- 64.
Bowett (1957), pp. 189–190.
- 65.
For instance, Brownlie claimed that there was no normative basis for limiting estoppel’s application to statements of fact: Crawford (2012), p. 421.
- 66.
Chagos Award (n 1) [429].
- 67.
ibid [430(a)].
- 68.
ibid [430(b)].
- 69.
ibid [430(c)].
- 70.
ibid [430(d)].
- 71.
ibid [430(e)].
- 72.
ibid [431(c)].
- 73.
ibid [431(d)].
- 74.
ibid [433].
- 75.
ibid [439].
- 76.
This limit was fixed at 12 miles from the lower waterline by BIOT Proclamation No. 1 of 1969.
- 77.
Chagos Award (n 1) [114]. At this point in time, Mauritius was not formally designated as a State for this purpose but the parties’ agree that Mauritian vessels were, in effect, designated to fish within this maritime zone at [116].
- 78.
ibid [118]. BIOT Ordinance 11 of 1984.
- 79.
BIOT Notice No. 7 of 1985.
- 80.
Via BIOT Proclamation No. 1 of 1991. The UK claimed that the FCMZ did not amount to an EEZ but the Tribunal viewed them as equivalent mechanisms. It was accompanied by the 1991 Fisheries and (Conservation and Management) Ordinance, which extended the licensing regime to cover this new zone. The 1991 Ordinance repealed the corresponding 1984 Ordinance.
- 81.
Chagos Award (n 1) [119].
- 82.
ibid [121]. Subsequently, on 13 August 2003, the UK government informed the Mauritian High Commissioner in London that the FCMZ was being transformed into an Environmental Protection and Preservation Zone (EPPZ). It was created pursuant to BIOT Proclamation No. 1 of 2003, on 17 September 2003. This newly declared zone had the same geographical reach as the FCMZ that it replaced.
- 83.
ibid [407].
- 84.
ibid [411].
- 85.
The UK had committed itself to using its ‘good offices’ with the US government to ensure that any fishing rights ‘would remain available […] as far as practicable’: ibid [412] and [449]. The UK argued that Mauritian fishing activities in the BIOT’s maritime zones could be categorised as minimal. It pointed out that, in some years, no applications for fishing licences had been made by Mauritian flagged vessels. Ibid [413]. Even if fishing activities were gauged by the Mauritian government’s preferred method of measuring the size of the catch it is hard to argue that Mauritian fishing activities in the Archipelago’s waters were significant: at [125]. However, the Tribunal took the view that the scale of Mauritian fishing activities in the BIOT’s maritime zones was not decisive at [450].
- 86.
ibid [408] (with the exception of the territorial waters immediately surrounding Diego Garcia).
- 87.
ibid [408–409].
- 88.
ibid [451].
- 89.
ibid.
- 90.
The Tribunal made it clear that it was only concerned with Mauritius’ claim, in relation to fishing rights, to the extent that it involved the Archipelago’s territorial sea, see ibid. at [455]. This is because Article 297(3)(a) of the LOSC provides that a coastal State is not obligated to submit to section 2 procedures in the case of a dispute relating to the exercise of its sovereign rights in respect of those living resources located in its EEZ. See Allen (2017).
- 91.
Chagos Award ibid [439]. The Tribunal decided that the UK government retained a discretion to maintain a balance between Mauritius’ fishing rights and the defence needs of the US government, at [452].
- 92.
ibid [439].
- 93.
ibid [440].
- 94.
ibid [442]. Thirlway observed that the principle of estoppel often involves a situation where the Applicant State has failed to do something when it might have been expected to act to protect its rights or at least to speak out. See (n 61) 37.
- 95.
Chagos Award, ibid.
- 96.
ibid.
- 97.
ibid [443].
- 98.
ibid [444].
- 99.
Mauritius advanced this argument, ibid [397].
- 100.
ibid [445].
- 101.
- 102.
ibid [447].
- 103.
ibid.
- 104.
- 105.
Chagos Award, ibid [448].
- 106.
Temple of Prear Vihear Case (Cambodia/Thailand) (1962) ICJ Reports 39.
- 107.
Fitzmaurice’s Separate Opinion in the Temple Case, 52, 63; cited in the Chagos Award (n 1) [437].
- 108.
ibid [446].
- 109.
ibid [444].
- 110.
ibid [408–409].
- 111.
It should be noted that the Tribunal was not prepared to accept that Mauritius’ fishing rights were unqualified. It preferred to stick closely to the commitments as they were expressed in the LHUs. See ibid [452].
- 112.
Bowett (1957), pp. 177–178.
- 113.
Article 31(3)(b) VCLT acknowledges that subsequent practice in the application of a given treaty may establish the agreement of the parties as to its interpretation. It should be acknowledged that a subsequent practice which is at odds with the meaning attributable to a treaty provision pursuant to Article 31(1) can lead to a new interpretation of the provision in question. However, in order for this to occur the practice would need to be sufficiently extensive and consistent to support the parties’ agreement as to the meaning of that provision. This amounts to a very high threshold and, of course, such a change must exist in relation to a valid treaty.
- 114.
Bowett (1957), pp. 177–178.
- 115.
ibid 178.
- 116.
Fitzmaurice’s Separate Opinion (n 106) at 63; Also see Sinclair (1996), pp. 104 and 107.
- 117.
Land and Maritime Boundary (Cameroon/Nigeria) Case (1998) ICJ Reps 303.
- 118.
ibid. [57].
- 119.
Thirlway (2005), pp. 1 and 22.
- 120.
ibid 23.
- 121.
ibid.
- 122.
- 123.
Aust, ibid p. 55.
- 124.
- 125.
Fitzmaurice, ibid. (italics in the original).
- 126.
See Thirlway (1990), pp. 29–30 and his analysis of the ICJ’s decision Gulf of Maine Case (Canada v USA) (1984) ICJ Reps 246. In this case an ICJ Chamber discussed estoppel’s normative basis. It observed that, ‘preclusion is in fact the procedural aspect and estoppel the substantive aspect of the same principle’ [130].
- 127.
- 128.
Thirlway (1990), p. 38.
- 129.
In accordance with the scope of a costal State’s authority in its EEZ. See Article 56(1) of the UN Convention on the Law of the Sea (‘LOSC’) (1982) 21 ILM 1261, (1994) 1833 UNTS 3.
- 130.
Koskenniemi (2005), p. 356.
- 131.
The Chagos Tribunal reiterated Arnold McNair’s classic standpoint in this regard. See Award (n 1), at [435].
- 132.
Koskenniemi (2005), p. 357.
- 133.
Cottier and Muller (2007) [3].
- 134.
Sinclair (1996), p. 107.
- 135.
ibid.
- 136.
See the ILC’s ‘Seventh Report of Special Rapporteur Víctor Rodríguez Cedeño on Unilateral Acts of States’, in the ILC’s 2004 Yearbook, Vol. 2, Part 1, 250, [103], cited in Kulick (2016), p. 109.
- 137.
Koskenniemi (2005), p. 358.
- 138.
ibid 356. Koskenniemi uses the example of unilateral declarations to illustrate this point.
- 139.
Hillgenberg (1999), p. 505.
- 140.
In accordance with the requirements set out in Article 31(1) VCLT.
- 141.
Hillgenberg (1999), p. 506.
- 142.
ibid.
- 143.
ibid, 505.
- 144.
Cottier and Muller (2007).
- 145.
See Sinclair (1996), 108 and 116. These cases include Temple Case (n 105); the North Sea Continental Shelf Cases (FR Germany/Denmark; FR Germany/Netherlands) (1969) ICJ Reps 3; the Gulf of Maine Case (n 125); the Military and Paramilitary Activities in and against Nicaragua (Nicaragua v USA) (Jurisdiction) Case (1984) ICJ Reps 392; Land, Island and Maritime Frontier Dispute (El Salvador v Honduras) (Application by Nicaragua to Intervene) (1990) ICJ Reps 92; and the Land and Maritime Boundary Case, (n 116).
- 146.
- 147.
Kulick (2016), pp. 124–125.
- 148.
Kulick (2016), p. 124.
- 149.
As envisaged by Judge Fitzmaurice in his Separate Opinion in the Temple Case (n 106).
- 150.
Kulick (2016), p. 125.
- 151.
Chagos Award (n 1) [417].
- 152.
ibid [547B].
- 153.
Article 287 sets out a choice of settlement procedures for the purposes of Part XV of the LOSC.
- 154.
See Talmon (2016), p. 18.
- 155.
ibid 18.
- 156.
Chagos Award (n 1) [534] and [535].
- 157.
Talmon (2016).
- 158.
Chagos Award (n 1) [519] and [520].
- 159.
ibid [514].
- 160.
Article 1(2) of the 1958 Convention which found its origins in the ILC’s Draft Articles. See ILC’s Draft Articles on the Law of the Sea and Commentaries, Eight Session (1956) UN Doc. A/3159, 265.
- 161.
Chagos Award (n 1) [515–517].
- 162.
ibid [517].
- 163.
ibid [517] and [520]. The Tribunal’s decision to use the notion of good faith as an interpretative device for the purposes of giving effect to estoppel is credible given that estoppel is underpinned by this meta-norm of international law. However, good faith possesses a mercurial quality and, as a consequence its content and application remain an uncertain affair. Consequently, the extent to which is can be a reliable guide to the act of interpretation is not at all clear. See Thirlway (1990), pp. 21–25; Thirlway (2005), pp. 7–10.
- 164.
Dissenting and Concurring Opinion appended to the Chagos Award, ibid. [94].
- 165.
ILC’s 1956 Report, 265, [5], quoted in the Dissenting and Concurring Opinion, ibid [93] and discussed in [94].
- 166.
Dissenting and Concurring Opinion, ibid.
- 167.
Chagos Award, ibid [516].
- 168.
ibid [519].
- 169.
ibid. It should be noted that the Tribunal did not have jurisdiction in respect of any fishing rights Mauritian vessels might enjoy in the BIOT’s EEZ as a result of the terms of Article 297(3)(a). Accordingly, the Tribunal was only concerned with Mauritius’ fishing rights to the extent that they related to the BIOT’s territorial sea. This was acknowledged by the Tribunal at [455].
- 170.
ibid [520].
- 171.
ibid [529].
- 172.
- 173.
Chagos Award, ibid [536].
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Allen, S. (2018). The Operation of Estoppel in International Law and the Function of the Lancaster House Undertakings in the Chagos Arbitration Award. In: Allen, S., Monaghan, C. (eds) Fifty Years of the British Indian Ocean Territory. The World of Small States, vol 4. Springer, Cham. https://doi.org/10.1007/978-3-319-78541-7_10
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