210
performing its duties in the exclusive economic zone, to have due regard to the
rights and duties of other States.
The Tribunal found that, in declaring the Marine Protected Area, the United
Kingdom had breached Mauritius’ fishing rights in the territorial sea, under Article
2(3) UNCLOS, and the undertakings to return the Chagos Archipelago to Mauritius
when no longer needed for defence purposes and to return the benefit of any minerals or oil discovered in or near the Archipelago to Mauritius, under Articles (2)3 and
56(2) UNCLOS. The said rights and undertakings were founded on the so called
‘Lancaster House Undertakings’ and the repetition thereof.
In the Chagos Marine Protected Area Arbitration, the expression ‘Lancaster
House Undertakings’ refers to the outcome of the meeting between the Mauritius
Council of Ministers and the United Kingdom, held in Lancaster House on 23
September 1965: the former agreed to the detachment of the Chagos Archipelago
and the latter undertook that Mauritius, once independent, would maintain fishing
rights and have the islands and the benefit of any minerals or oil discovered in or
near the Archipelago back.
80
The question thus arose about the legal effect of the
United Kingdom’s commitments, also considering the disagreement of the Parties
on the nature and scope of the Lancaster House Undertakings.
The determination of the legal effect of the United Kingdom’s commitments was
essential for the application of Articles 2(3) and 56(2) UNCLOS, which depended
on the possibility to link those undertakings to the “other rules of international law”
in Article 2(3) and to the “rights and duties of other States” in Article 56(2). In
addressing the question about the nature of the Lancaster House Undertakings, the
Tribunal adopted a three-step approach based on the Parties’ intent in 1965, the
legal status of the Lancaster House Undertakings, and the legal significance of the
United Kingdom’s repetition of its undertakings.
81
Firstly, the Tribunal held that the United Kingdom meant to be bound by the
commitments it made in Lancaster House in 1965.
82
In this connection, the Tribunal
took into account the importance of the United Kingdom’s undertakings, in the
absence of which the Mauritius Council of Minister would have not agreed to the
detachment of the Chagos Archipelago.
83
Secondly, the Tribunal excluded any international relevance of the Lancaster House Undertakings in the period from 1965 to
1968, since Mauritius was then a colony of the United Kingdom rather than an
independent State. Nonetheless, it found that the independence of Mauritius had the
effect of “transforming the commitments made in 1965 into an international agreement” (sic!) by reason of the subject matter and the fulfilment of the pertinent conditions, namely Mauritius’ independence and the United Kingdom’s retention of the
Chagos Archipelago.
84
Thirdly, with regard to the United Kingdom’s repetition of
80 Chagos Marine Protected Area Arbitration, para. 77.
81 Ibidem, para. 420.
82 Ibidem, para. 423.
83 Ibidem, para. 422.
84 Ibidem, paras 424–428. For a different viewpoint on the international relevance of the Lancaster
House Undertakings see Allen (2014), pp. 102–130, and Biad and Edynak (2016) pp. 75–76, all of
M. Gervasi
performing its duties in the exclusive economic zone, to have due regard to the
rights and duties of other States.
The Tribunal found that, in declaring the Marine Protected Area, the United
Kingdom had breached Mauritius’ fishing rights in the territorial sea, under Article
2(3) UNCLOS, and the undertakings to return the Chagos Archipelago to Mauritius
when no longer needed for defence purposes and to return the benefit of any minerals or oil discovered in or near the Archipelago to Mauritius, under Articles (2)3 and
56(2) UNCLOS. The said rights and undertakings were founded on the so called
‘Lancaster House Undertakings’ and the repetition thereof.
In the Chagos Marine Protected Area Arbitration, the expression ‘Lancaster
House Undertakings’ refers to the outcome of the meeting between the Mauritius
Council of Ministers and the United Kingdom, held in Lancaster House on 23
September 1965: the former agreed to the detachment of the Chagos Archipelago
and the latter undertook that Mauritius, once independent, would maintain fishing
rights and have the islands and the benefit of any minerals or oil discovered in or
near the Archipelago back.
80
The question thus arose about the legal effect of the
United Kingdom’s commitments, also considering the disagreement of the Parties
on the nature and scope of the Lancaster House Undertakings.
The determination of the legal effect of the United Kingdom’s commitments was
essential for the application of Articles 2(3) and 56(2) UNCLOS, which depended
on the possibility to link those undertakings to the “other rules of international law”
in Article 2(3) and to the “rights and duties of other States” in Article 56(2). In
addressing the question about the nature of the Lancaster House Undertakings, the
Tribunal adopted a three-step approach based on the Parties’ intent in 1965, the
legal status of the Lancaster House Undertakings, and the legal significance of the
United Kingdom’s repetition of its undertakings.
81
Firstly, the Tribunal held that the United Kingdom meant to be bound by the
commitments it made in Lancaster House in 1965.
82
In this connection, the Tribunal
took into account the importance of the United Kingdom’s undertakings, in the
absence of which the Mauritius Council of Minister would have not agreed to the
detachment of the Chagos Archipelago.
83
Secondly, the Tribunal excluded any international relevance of the Lancaster House Undertakings in the period from 1965 to
1968, since Mauritius was then a colony of the United Kingdom rather than an
independent State. Nonetheless, it found that the independence of Mauritius had the
effect of “transforming the commitments made in 1965 into an international agreement” (sic!) by reason of the subject matter and the fulfilment of the pertinent conditions, namely Mauritius’ independence and the United Kingdom’s retention of the
Chagos Archipelago.
84
Thirdly, with regard to the United Kingdom’s repetition of
80 Chagos Marine Protected Area Arbitration, para. 77.
81 Ibidem, para. 420.
82 Ibidem, para. 423.
83 Ibidem, para. 422.
84 Ibidem, paras 424–428. For a different viewpoint on the international relevance of the Lancaster
House Undertakings see Allen (2014), pp. 102–130, and Biad and Edynak (2016) pp. 75–76, all of
M. Gervasi