THE GULF OF SIAM: OFFSHORE CONCESSION PROBLEMS

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP08C01297R000300190002-9
• Release Decision: RIFPUB
• Original Classification: C
• Document Page Count: 11
• Document Creation Date: December 27, 2016
• Document Release Date: September 11, 2012
• Sequence Number: 2
• Publication Date: April 27, 1970
• Content Type: REPORT

27 APR 7c,
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RESEARCH STUDY
BUREAU OF INTELLIGENCE AND RESEARCH
April 27, 1970
THE GULF OF SIAM: OFFSHORE CONCESSION PROBLEM
Cambodia and Thailand have granted overlapping petroleum concessions
in the Gulf of Siam. The Embassy in Bangkok has requested that The
Geographer examine the shelf boundaries and prepare alternative median
and lateral lines. This study discusses the boundary problem and pro- A
poses alternatives.
L=5
ABSTRACT
Four states--Malaysia, Thailand, Cambodia and Viet-Nam--
border on the semi-enclosed Gulf of Siam. Malaysia has been
actively pursuing a policy of resolving offshore boundary
questions through international agreement and appears to have
no immediate problems in the Gulf. Thailand has decreed a
provisional shelf boundary for petroleum concessions with
respect to the above three states based upon a modified equi-
distance principle which utilizes selective bpepoints to the
advantage of Thailand. Five U.S. firms, including TENNECO,
AMOCO, CONOCO, Gulf and Union Oil, and one British firm
currently have concessions. The zones of these concessions are
shown on Map A; the shaded area is also encompassed in the
Cambodian concession area.
This report was produced by the Bureau
of lntelligenee4 and Research. Aside
from normal substantive exchange with
other agencies at the working level,
it has not been coordinated elsewhere.
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CON
AL/NO FOREIGN DISSEM
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The Cambodian shelf boundary also utilizes a modified equidistance
principle choosing basepoints advantageous to Cambodia. The French
combine ELF/ERAP has been granted a concessibn for the entire zone.
Cambodia, moreover, has included within its continental shelf the
Vietnamese-claimed islands of Phu Quoc and Han Panjang. These islands
are also principal basepoints. Map B shows the limits of the Cambodian
concession area.
Viet-Nam, in contrast, has not granted concessions but has
created, as a preliminary step, an exploration zone, shown on Map B.
The "disputed" area with Cambodia is extensive even though Viet-Nam
has not, as yet, included Phu Quoc and other claimed islands within
its zone.
The Geneva Convention on the Continental Shelf does not prescribe
any one method of determining shelf boundary lines. The Convention
provides that the equidistance method should be used unless the
parties have not reached agreement on another method of delimitation
or unless there are "special circumstances." The
Geographer has constructed three potential equidistance lines on Map B.
Line 1 uses all basepoints from which the territorial sea may be
measured. Line 2 eliminates certain small rocks and islets close to
this equidistance line which, if used, would change the lines out of pro-
portion to their size or importance. The third line omits all islands not
adjacent to the coasts of the states. For the most part, these three
lines are situated between the shelf boundaries claimed by Thailand
and Cambodia,
CONFIDENTIAL/NO FOREIGN DISSEM
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CONFIDENTIAL/NO FOREIGN MSSEM
.111
The International Court of Justice, however, has stated that
one factor in determining the proper shelf boundary between states
Is the measure of proportionality between the length of the claimant
states' shorelines and the shelf to be allocated. Applying this
criterion the Cambodian claim is excessive; the Thai claim is
slightly modest.
CONFIDENTIAL/NO FOREIGN MSSEM
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BACKGROUND
The Gulf of Siam, a semi-enclosed arm oftthe South China Sea, extends
approximately 375 nautical miles into the Southeast Asian landmass.
Ranging in width from 40 nautical miles in the north to approximately 250
nautical miles in the south, the Gulf has an area of 84,606 square nautical
miles. Four states--Malaysia, Thailand, Cambodia, and Viet-Nam have
shores bordering on the Gulf. Their individual coastlines measure approxi-
mately 10,900, 150, and 155 nautical miles, respectively. Since the
waters of the entire Gulf are less than 200 meters in depth the entire
seabed qualifies as a legal continental shelf under the definition
contained in Article 1 of the Geneva Convention on the Continental Shelf.
Malaysia
The last three turning points (Nos. 18 - 20) of the Indonesian-
Malaysian continental shelf agreement are plotted on Map No. 2 as a dash
and "x" line. While the shelf boundary is actually beyond the geographical
limits of the Gulf of Siam, the terminus (No. 20) is a trisection point,
equidistant from Malaysian, Indonesian and Vietnamese territory. 1
In contrast, no agreement has been signed between Thailand and Malaysia
dividing the continental shelf at this date. However, the 30,000 square
mile (Indonesian) ESSO concession does not appear, from cartographic
evidence, to conflict appreciably, if at all, with the adjacent Thai
concession zone.
Thailand
The Government of Thailand proclaimed on May 16, 1968 a Tentative
Border Line for the Thai Continental Shelf. The extent of this boundary
and the shelf concession areas, with current concession holders, is shown
on Map No. 1. Five American based firms--TENNECO, AMOCO, Gulf, CONOCO,
and Union Oil of California--and one British firm, BP, currently hold
seven concession zones while two areas, adjacent to Malaysia, are open.
The total Thai concession zone has an area of 55,718 square nautical
miles.
The concept behind the delimitation of the Thai continental shelf
boundary appears to be a variation of the equidistance principle which
uses as basepoints only the mainlands of the two states and selected
large, onshore islands. Cambodian islets, distant from the mainland, have
been ignored. The Thai continental shelf boundary is shown on Map B
by a series of crosses.
1. See International Boundary Study - Series A: Limits in the Sea- No. 1,
dated January 21, 1970.
rnmrrnrmrTAI /MA- rnnrrnm nrecru
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CONFIDENTIAL/NO FOREIGN DISSEM
-2-.
Cambodia
The Cambodian continental shelf boundary., as determined from a
Cambodian chart, is shown on Map B by'a solid line.'The area in
potential conflict with Thailand is shaded on Map A. The Cambodian
continental shelf zone is estimated to include approximately 30,000 square
nautical miles of shelf. The French combine ELF/ERAP will have the
concession area. The continental shelf boundary, as with Thailand,
follows a selective equidistance principle. The equidistance line, where
the two states are adjacent, follows a set azimuth from the shore to a
point in the middle of the Gulf where the states become opposite. This
line, which is equidistant from both Thai and Cambodian shores at the
beginning, would, if continued, cut across the Thai island of Ko Kut.
As a result, the Cambodian shelf boundary employs an equidistant line
which circumscribes Ko Kut to the south where the intervening water body
is less than 24 nautical miles, and by a series of 12 nautical mile arcs
from Ko Kut where the water width is greater than 24 nautical miles. The
original azimuth is rejoined west of Ko Kut and extends to a midpoint
which is between the Cambodian coast and the Thai shore forming the
western edge of the Gulf. The northern and eastern Thai shores of the
Gulf and the many associated islands including Ko Kut are not utilized
in the creation of the equidistance line.
The line southward from the midpoint, i.e. where Cambodia and
Thailand are opposite, is an equidistance line measured from base points
on the island groups of Poulo Wal and Han Panjang in the east and on
the Thai-Malaysian shore or on large Thai islands immediately adjacent
to the shore in the west. The southern extension of this median line
is based on the premise of Cambodian sovereignty over Panjang and Phu
Quoc, both of which would be disputed by the Government of Viet-Nam.
These island groups are situated south of the Brevie Line, established
by the French in 1939 as the administrative dividing line between
Cambodia and (the then colony of) Cochin-China. Strangely, however, the
boundary, close to the shore, leaves the "Southern Pirate" islands to
Viet-Nam; these islands have been consistently claimed by Cambodia.
Viet-Nam
To our knowledge, offshore concession zones have not yet been
established by Viet-Nam although an exploration zone has been decreed.
Its limits are shown on Map B by a dotted line. While a significant
overlap occurs between the Cambodian continental shelf boundary and the
Vietnamese exploration zone, an even greater zone of potential conflict
could occur with the inclusion of Phu Quoc in a Vietnamese concession zone.
Law of the Sea Principles
The Geneva Convention on the Continental Shelf, which entered into
force in June 1964, states in Article 6:
CONFIDENTIAL/NO FOREIGN DISSEM
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- 3 -
"1. Where the same continental shelf is adjacent to the
territories of two or more states whose coasts are opposite
each other, the boundary of the continental shelf appertaining
to such states shall be determined by agreement between them.
In the absence of agreement, and unless another boundary is
justified by special circumstances, the boundary is the
median line, every point of which is equidistant from the
nearest point of the baselines from which the breadth of
the territorial sea of each state is measured.
2. Where the continental shelf is adjacent to the territories
of two adjacent states, the boundary of the continental shelf
shall be determined by agreement between them. In the
absence of agreement, and unless another boundary line is
justified by special circumstances, the boundary shall be
determined by application of the principle of equidistance
from the nearest points of the baselines from which the -
breadth of the territorial sea of each state is measured."
The question of whether Article 6(2) has become a principle of customary
international law was referred to the International Court of Justice. In
its February 1969 decision in the North Sea Continental Shelf Case' the
Court decreed that "the Geneva Convention did not embody or crystallize
any pre-existing or emergent rule of customary law, according to which
the delimitation of continental shelf area between adjacent States must,
unless the Parties otherwise Agree, be carried out on an equidistance-
special circumstances basis."4 The Court's ruling was directed at Germany,
a non-signatory state. Both Thailand and Cambodia, in contrast, have
signed and ratified the Convention.
The Court referred to the requirement of delimitation "by agreement,
in accordance with "equitable principles" which take into account "all
the,relevant circumstances." Parties are under an obligation "to enter
into negotiations with a view to arriving at an agreement, and not merely
to go through a formal process of negotiation as a sort of prior condition
for the automatic application of a certain method of delimitation in the
absence of an agreement."
1. North Sea Continental Shelf, Judgment, International Court of Justice
Report, 1969.
2. Ibid., par. 69.
3. Ibid., par. 101
4. Ibid., par. 85.
CONFIDENTIAL/NO FOREIGN DISSEM
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CONFIDENTIAL/NO FOREIGN DISSEM
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CONCLUSIONS
The Court decision repeatedly refers to the inapplicability of
reliance on the equidistance principle alone for the determination of shelf
boundaries between adjacent states. "The conclusion drawn by the Court...
is that the notion of equidistance as being logically necessary, in the
sense of being an inescapable a priori accompaniment of basic continental
shelf doctrine, is incorrect." 1 The Court stressed the need to negotiate
to obtain an agreement to arrive at an equitable division of the shelf.
In response to the Embassy's request, three equidistance lines have
been constructed on Map 8 in addition to the Thai and Cambodian lines.
The first equidistance line, represented by a dashed symbol, utilizes
all basepoints from which the territorial sea of all states can be -
measured. The line has been extended to divide the shelves of the four
states adjacent to the Gulf. The technique applied gives equal value to
a small, isolated rock as to the mainland. In certain instances, as in
the Saudi-Iranian, Abu Dhabi-Qatar and Italian-Yugoslav negotiations,
rocks and islets close to the median line, which would exert undue
influence in relation to their size and general value, have been ignored
or given a diminished influence. The second equidistance line, the
dash-dot symbol, follows this technique. The small Cambodian islets of
Veer and Kusrovie, which push the lateral line far northward, have been
ignored.
The third equidistance line, dash-double-dot symbol, ignores all
islands not immediately adjacent to the mainlands of the states. These
three equidistance lines fall, for the most part, between the Cambodian
and Thai lines. (The area of discrepancy in the northwest may be due to
errors of plotting stemming from scale or projection factors of the charts
utilized.)
As noted, however, the International Court favored an equitable
distribution of the seabed taking into consideration all factors
outlined in the decision. The case involved the German claim that the
existence of a concave coastline gave Germany a disadvantaged position in
the construction of equidistance lines in a semi-enclosed sea. The
Court, in summing its decision, stated "A final factor to be taken account
of is the element of reasonable degree of proportionality which a
delimitation effected according to equitable principles ought to bring
about between the extent of the continental shelf appertaining to the?
states concerned and the lengths of their respective coastlines..." 4
1. Ibid., par. 46.
2. Ibid., par. 98.
CONFIDENTIAL/NO FOREIGN DISSEM
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