192
1 Background. The Dispute Between Mauritius
and the United Kingdom on Sovereignty Over the Chagos
Archipelago
The Chagos Archipelago lies approximately in the centre of the Indian Ocean and
consists of 7 atolls including 55 islands, the major one of which is Diego Garcia.
The Archipelago had been part of the British colony of Mauritius until 1965,
1
when
the United Kingdom detached it from Mauritius in order to create a new colony, the
British Indian Ocean Territory (BIOT), comprising also three islands later returned
to the Seychelles, namely Aldabra, Farquahr and Desroches.
2
Since then, the Chagos
Archipelago has remained part of the BIOT, even though Mauritius gained independence in 1968.
In 1966 the United Kingdom and the United States entered into an agreement
stipulating the availability of the BIOT to meet their needs for defence (BIOT
Agreement).
3
It was followed by supplementary agreements and amendments as
well as exchanges of letters and diplomatic practice.
4
Further to an exchange of
notes constituting an agreement in 1972,
5
the United States was entitled “to construct, maintain and operate a limited naval communications facility on Diego
Garcia”.
6
The 1972 Diego Garcia Agreement was terminated in 1976,
7
when the
1 For an excursus on the history of the Chagos Archipelago, dating back to the discovery thereof,
see Abraham (2011), pp. 69–89, and Robertson (2012), pp. 3–6.
2 The three islands were eventually returned to the Seychelles just before its independence in 1976.
Since then, only the Chagos Archipelago has composed the British Indian Ocean Territory. As a
consequence, the 1966 BIOT Agreement, which—as will be explained shortly—stipulated the
availability of the BIOT to meet the United Kingdom’s and United States’ needs for defence, was
amended to remove any reference to Aldabra, Farquahr and Desroches in the definition of the
British Indian Ocean Territory. In this connection, see the Exchange of Notes between the
Government of the United Kingdom of Great Britain and Northern Ireland and the Government of
the United States of America amending the Agreement of 30 December 1966 concerning the
Availability for Defence Purposes of the British Indian Ocean Territory, 22 June 1976, entered into
force on that day.
3 Exchange of Notes between the Government of the United Kingdom of Great Britain and
Northern Ireland and the Government of the United States of America concerning the Availability
for Defence Purposes of the British Indian Ocean Territory, 30 December 1966, entered into force
on signature (hereinafter, the BIOT Agreement).
4 For an overview of the agreements and the amendments thereof between the United Kingdom and
the United States on Diego Garcia, see Oraison (2004), pp. 130–140.
5 Exchange of Notes between the Government of the United Kingdom of Great Britain and
Northern Ireland and the Government of the United States of America concerning a Limited United
States Naval Communications Facility on Diego Garcia, British Indian Ocean Territory, 24 October
1972, entered into force on that day (hereinafter, the 1972 Diego Garcia Agreement).
6 1972 Diego Garcia Agreement, para. 1(a).
7 Exchange of Notes between the Government of the United Kingdom of Great Britain and
Northern Ireland and the Government of the United States of America concerning a United States
Navy Support Facility on Diego Garcia, British Indian Ocean Territory, 25 February 1976, entered
into force on that day.
M. Gervasi
1 Background. The Dispute Between Mauritius
and the United Kingdom on Sovereignty Over the Chagos
Archipelago
The Chagos Archipelago lies approximately in the centre of the Indian Ocean and
consists of 7 atolls including 55 islands, the major one of which is Diego Garcia.
The Archipelago had been part of the British colony of Mauritius until 1965,
1
when
the United Kingdom detached it from Mauritius in order to create a new colony, the
British Indian Ocean Territory (BIOT), comprising also three islands later returned
to the Seychelles, namely Aldabra, Farquahr and Desroches.
2
Since then, the Chagos
Archipelago has remained part of the BIOT, even though Mauritius gained independence in 1968.
In 1966 the United Kingdom and the United States entered into an agreement
stipulating the availability of the BIOT to meet their needs for defence (BIOT
Agreement).
3
It was followed by supplementary agreements and amendments as
well as exchanges of letters and diplomatic practice.
4
Further to an exchange of
notes constituting an agreement in 1972,
5
the United States was entitled “to construct, maintain and operate a limited naval communications facility on Diego
Garcia”.
6
The 1972 Diego Garcia Agreement was terminated in 1976,
7
when the
1 For an excursus on the history of the Chagos Archipelago, dating back to the discovery thereof,
see Abraham (2011), pp. 69–89, and Robertson (2012), pp. 3–6.
2 The three islands were eventually returned to the Seychelles just before its independence in 1976.
Since then, only the Chagos Archipelago has composed the British Indian Ocean Territory. As a
consequence, the 1966 BIOT Agreement, which—as will be explained shortly—stipulated the
availability of the BIOT to meet the United Kingdom’s and United States’ needs for defence, was
amended to remove any reference to Aldabra, Farquahr and Desroches in the definition of the
British Indian Ocean Territory. In this connection, see the Exchange of Notes between the
Government of the United Kingdom of Great Britain and Northern Ireland and the Government of
the United States of America amending the Agreement of 30 December 1966 concerning the
Availability for Defence Purposes of the British Indian Ocean Territory, 22 June 1976, entered into
force on that day.
3 Exchange of Notes between the Government of the United Kingdom of Great Britain and
Northern Ireland and the Government of the United States of America concerning the Availability
for Defence Purposes of the British Indian Ocean Territory, 30 December 1966, entered into force
on signature (hereinafter, the BIOT Agreement).
4 For an overview of the agreements and the amendments thereof between the United Kingdom and
the United States on Diego Garcia, see Oraison (2004), pp. 130–140.
5 Exchange of Notes between the Government of the United Kingdom of Great Britain and
Northern Ireland and the Government of the United States of America concerning a Limited United
States Naval Communications Facility on Diego Garcia, British Indian Ocean Territory, 24 October
1972, entered into force on that day (hereinafter, the 1972 Diego Garcia Agreement).
6 1972 Diego Garcia Agreement, para. 1(a).
7 Exchange of Notes between the Government of the United Kingdom of Great Britain and
Northern Ireland and the Government of the United States of America concerning a United States
Navy Support Facility on Diego Garcia, British Indian Ocean Territory, 25 February 1976, entered
into force on that day.
M. Gervasi