      DISSENTING OPINION OF JUDGE AD HOC DUGARD

   Malaysia has original title to Pedra Branca/Pulau Batu Puteh — Construc-
 ion of Horsburgh lighthouse did not alter situation — 1953 correspondence of
uncertain meaning and authorization — Failure of Singapore to publicize 1953
correspondence confirms its inconsequential nature — Court wrong to attach
 ignificance to 1953 correspondence — Conduct of Parties between 1953 and
1980 equivocal — No inferences on sovereignty to be drawn from this period —
Singapore’s conduct consistent with that of lighthouse operator — Court errs in
 nterpretation of facts of this period — Legal basis for Court’s decision
unclear — Court correctly rejects prescription and estoppel — Court’s decision
 hat conduct of Parties displayed tacit agreement or understanding on passing
of sovereignty unconvincing in law and on facts — Insufficient evidence to sup-
port finding that Malaysia acquiesced in Singapore’s claim to sovereignty —
Requirements for acquisition of territory set out in Eritrea/Yemen Arbitration
Award — Such requirements not satisfied in present case — Title to Pedra
Branca/Pulau Batu Puteh remains with Malaysia — Middle Rocks and South
Ledge fall within sovereignty of Malaysia — Unfortunate that counsel not
 nvited to address Court on legal basis for Court’s decision.

   1. The Court’s Judgment provides an equitable solution to the dispute
before it. Pedra Branca/Pulau Batu Puteh is awarded to Singapore ; Mid-
dle Rocks is awarded to Malaysia ; and South Ledge, a low-tide eleva-
 ion, will be allocated to the State in the territorial waters of which it is
 ocated. Although the dispute was not, at least in theory, about territorial
sea and continental shelf, both Parties will share these areas and their
resources. If this Court was sitting as a court of equity, or if it had been
authorized by the Parties to decide the case ex aequo et bono in terms of
Article 38, paragraph 2, of the Statute of the Court, I might have been
able to agree with the Court’s Judgment. The Court is not, however, sit-
 ing as a court of equity. The Special Agreement entered into between
Malaysia and the Republic of Singapore on 6 February 2003 makes it
clear, in Article 5, that the dispute is to be resolved in accordance with
 nternational law. As I find it impossible to agree with the Court’s rea-
soning on the law, and its interpretation of the facts upon which this legal
reasoning is based in respect of the question of sovereignty over Pedra
Branca/Pulau Batu Puteh, I must dissent on this issue.
   2. The majority judgment of a court the size of that of the Interna-
 ional Court of Justice inevitably must take account of different judicial
views and will reflect the lowest common denominator of the majority.

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Even allowing for this, I find it difficult to fully comprehend the basis
 or the Court’s Judgment. The Judgment is premised on the finding that
 he conduct of both Parties has resulted in the passing of sovereignty
over Pedra Branca/Pulau Batu Puteh from Malaysia (previously Johor)
 o Singapore. While considerations of acquiescence, abandonment of
 itle and tacit agreement or understanding feature prominently in the
Court’s reasoning, no attempt is made to justify or explain the passing
of sovereignty in terms of accepted principles governing the acquisition
of territorial title. At the same time the interpretation of the facts of the
case gives rise for concern. The facts of the dispute are complex, con-
 radictory and complicated. In reaching its final decision the Court has
been compelled to choose between competing facts and to attach more
weight to some facts than to others. This is the nature of fact finding in
 he judicial process. In my view, however, the Court has allowed itself,
 n making its choice of facts and the weight to be attached thereto, par-
 icularly in respect of the period 1953 to 1980, to be unduly influenced
by its interpretation of the controversial correspondence of 1953 between
Singapore and Johor. It has been very kind to Singapore in its assess-
ment of the facts of this period and less kind to Malaysia. My disagree-
ment with the Court on both facts and law are examined in this
opinion.

                         THE FACTS BEFORE 1852

   3. I have little disagreement with the Court in respect of events that
occurred before 1852. I agree with findings and reasoning of the Court
 hat Johor (and hence Malaysia) had sovereignty over Pedra Branca/Pu-
 au Batu Puteh before 1824 and that nothing occurred between that date
and 1844 to affect this conclusion. The Court is correct in deciding that
 n all probability W. G. Butterworth, Governor of the Straits Settlement,
wrote to the Sultan and Temenggong of Johor in November 1844 pro-
posing the construction of the Horsburgh lighthouse in general terms,
 hat is not only for it to be built on Peak Rock but also in other possible
 ocations. However, I disagree with the Court that the Governor
“appears” not to have identified Pedra Branca/Pulau Batu Puteh as a
possible alternative location (Judgment, para. 134). The correspondence
preceding Governor Butterworth’s letters indicates that Pedra Branca/
Pulau Batu Puteh was always an alternative location and one identified
as a possible site for the construction of the lighthouse before Peak Rock
was suggested. Thus it is a highly reasonable inference that Pedra Branca/
Pulau Batu Puteh was expressly mentioned as an alternative site in Gov-
ernor Butterworth’s letters. This disagreement is not crucial to the out-
come of the case as the Court seems to have accepted that sovereignty
over the island remained with Johor when the lighthouse was con-
structed. In any event, it “does not draw any conclusions about sover-

126

eignty based on the construction and commissioning of the lighthouse”
 Judgment, para. 162).

   4. The Court makes no finding on the question whether Johor ceded
any island (including Pedra Branca/Pulau Batu Puteh) under its sover-
eignty, that might be chosen for the construction of the lighthouse, to the
United Kingdom (and hence Singapore) or whether it granted only per-
mission to build, maintain and operate a lighthouse on the island selected.
The reason for this is that the Court was left “in real doubt” about what
Governor Butterworth had proposed to the Sultan and Temenggong of
Johor in 1844 (ibid., para. 133). The Court was, however, satisfied that
Johor’s sovereignty over Pedra Branca/Pulau Batu Puteh before 1844 had
already been established.

                        THE PERIOD 1852 TO 1952

   5. There is an ambivalence on the part of the Court in its treatment of
 he period 1852 to 1952. In large measure this is because of the failure of
 he Court to reach any conclusion on the question whether Pedra Branca/
Pulau Batu Puteh had been ceded to the United Kingdom in 1844 or
whether it had merely been given permission to construct, maintain and
operate the lighthouse on the island (see above, paragraph 4). The Court
considers the conduct of the Parties during this period and carefully scru-
 inizes events occurring during this period that might have some bearing
on the sovereignty over the island, but reaches no conclusion on the ques-
 ion of sovereignty over the island.
   6. The Court examines British legislation dealing with the straits lights
system, which allowed Singapore to administer lighthouses which had no
 erritorial connection with Singapore, and rightly finds that it did not
demonstrate British sovereignty over the islands on which lighthouses
were constructed. However, it then finds, in respect of the post 1952-
period, that a claim that Pedra Branca/Pulau Batu Puteh belonged to
Singapore, included in the drafting history of a 1958 amendment to the
1957 Light Dues Ordinance (Singapore), gives “support to Singapore’s
contentions” (Judgment, para. 174). In my view such a claim in the draft-
 ng history of a statute does not warrant even so weak a conclusion.
Another fact of doubtful significance viewed as having “some signifi-
cance” by the Court is the fact that in 1952 Johor considered assuming
responsibility for the funding of the Pulau Pisang Lighthouse, which
clearly falls within Malaysia’s sovereignty, but not for Pedra Branca/Pu-
 au Batu Puteh. On the other hand, the Court does not attach signifi-
cance to the failure of the 1927 Straits Settlement and Johor Territorial
Waters Agreement, which dealt with the retrocession of certain islands
ceded by Johor to Singapore in 1824, to include Pedra Branca/Pulau
Batu Puteh within Singapore’s territory. It is true, as the Court finds, that
Pedra Branca/Pulau Batu Puteh did not fall within the scope of the

127

Agreement, but one would at the very least have expected Singapore to
have insisted on some mention that the island belonged to Singapore —
had it at this time indeed claimed sovereignty over the island.

  7. Events occurring between 1852 and 1952 are largely viewed by the
Court as having no significance or being of little significance. This brings
one to 1953 which is seen by the Court as the turning point in respect of
sovereignty over Pedra Branca/Pulau Batu Puteh.

                        THE 1953 CORRESPONDENCE

   8. The year 1953 was, in the language of the Court (Judgment,
para. 203), of “central importance” to an understanding of the dispute,
 or in that year the Acting State Secretary of Johor wrote to Singapore
 nforming it that Johor (Malaysia) did not claim “ownership” of Pedra
Branca/Pulau Batu Puteh. This admission is correctly seen by the Court
as highly significant but whether it, together with preceding or subse-
quent events, provides evidence that sovereignty over the island was now
with Singapore is another matter. In my view there are too many ques-
 ions, too many doubts, surrounding the 1953 exchange of correspond-
ence between Singapore and Johor and its aftermath to justify the con-
clusion that Johor’s letter in effect, if not in form, resulted in the transfer
of sovereignty over Pedra Branca/Pulau Batu Puteh from Johor to Sing-
apore.
   9. First, the Singapore Colonial Secretary did not ask where sover-
eignty over Pedra Branca/Pulau Batu Puteh lay, but whether the island
had been leased, granted or ceded to Singapore. Had Singapore’s letter
expressly asked which State had sovereignty over or territorial title to the
 sland, and had Johor stated that it did not claim sovereignty or territo-
rial title, it would have been possible to conclude that Johor (Malaysia)
had abandoned any claim to sovereign title over the island. But Singa-
pore’s letter confused the language of private law and public law and
 nstead asked whether the island had been leased, subjected to a grant or
ceded to Singapore. Not surprisingly, therefore, the reply made use of the
 anguage of private law — ownership — not that of public law — sov-
ereignty. And it cannot be denied that there is a difference between own-
ership and sovereignty.

   10. The Court’s comment on “ownership” and “sovereignty” is not
convincing. It acknowledges that “in law” ownership is distinct from sov-
ereignty but asserts that the enquiry by Singapore was directed at Singa-
pore’s sovereignty over Pedra Branca/Pulau Batu Puteh. It then adds that
“[i]n international litigation ‘ownership’ over territory has sometimes
been used as equivalent to ‘sovereignty’” (ibid., para. 222). In support of
 his proposition it cites Territorial Sovereignty and Scope of the Dispute,

128

Eritrea/Yemen ((1998) 22 RIAA, pp. 209, 219, para. 19 and pp. 317-318,
para. 474). This calls for two responses. First, as shown above (see para-
graph 9 above), the letter of request itself confused property law and
 nternational law by asking whether there was “any document showing a
 ease or grant of the rock or whether it had been ceded by the Govern-
ment of the State of Johore or in any other way disposed of” (Judgment,
para. 192). Secondly, the Eritrea/Yemen Arbitration Award does not
equate “ownership” with “sovereignty”. The passages cited, use the word
“ownership” loosely to mean “sovereignty” but, when it comes to the dis-
positif, the Tribunal is careful to use the word sovereignty in respect of
 he islands (Eritrea/Yemen, op. cit., pp. 330-331, para. 527). In the
present case it is not clear — and this is the reason for uncertainty —
whether the Acting State Secretary used the word “ownership” loosely to
mean sovereignty or whether he deliberately used the property law term
of ownership to indicate that as far as Johor was concerned Singapore
owned the land on which the lighthouse was built.

   11. Secondly, there is the question why the Acting State Secretary of
Johor consulted the Commissioner for Lands and Mines and Chief Sur-
veyor, who would have been able to advise mainly on private law issues,
rather than his political and foreign affairs advisers . Was this because he
 ailed to see the matter as one affecting sovereignty over Pedra Branca/
Pulau Batu Puteh ? Is this why he used the word ownership ? And what
did he mean by ownership in the context of the historical circumstances
relating to the island ? Full ownership ? Residual ownership ? Possession?
Or sovereignty ?

  12. That the Acting State Secretary saw his role as limited to internal,
private law affairs is confirmed by the written response of Singapore to
 he question put by Judge Keith on 23 November 2007. Singapore refers
 o the fact that during the period in question “Johor officials continued
 o correspond routinely with their counterparts in Singapore on matters
under their charge” (Written response of Singapore to the question put
by Judge Keith dated 30 November 2007). Examples of such contact and
correspondence given by Singapore concerned the supply of water, co-
operative policing and relations between Singapore and the Johor Har-
bour Master and Johor Controller of Supplies. None of these matters
concerned political, external affairs of the kind reserved for Great Britain
under the Federation of Malaya Agreement of 1948.

   13. Thirdly, why did the Government of Singapore not ask for clari-
fication as to the meaning of “ownership” ? Surely it must have been un-
certain as to exactly what this meant ? Did it fail to publicize the letter of

129

Johor because this might have prompted an unfavourable clarification or
explanation from Johor ? The Court’s assertion that Johor’s reply “is
clear in its meaning” (Judgment, para. 223) fails to address questions of
 he kind raised in paragraphs 9 to 13 of the Judgment.

   14. Fourthly, there is the vexed question whether the Acting State Sec-
retary of Johor had the authority to pronounce on matters of sovereignty
 as opposed to ownership) ? The Parties strongly disagreed on the subject.
Malaysia maintains that two agreements of 1948, between the British
Crown and the Sultan of Johor and the Federation of Malaya respec-
 ively, withheld power in respect of external affairs from the State of
Johor in favour of Great Britain. Singapore, on the other hand, argues
 hat the 1953 correspondence did not relate to external affairs and that
 he principle of omnia praesumuntur rite esse acta applied to the 1953
 etter. The Court’s brief conclusion that the 1948 Agreements were not
relevant, because the correspondence was initiated by a representative of
 he British Crown which was not a foreign State, and because a response
 o a request for information could not be described as the exercise of
executive authority in respect of external affairs, do not in my view sat-
 sfactorily answer the constitutional objections raised by Malaysia to the
authority of the Acting State Secretary to pronounce on sovereignty over
Pedra Branca/Pulau Batu Puteh. This is a matter that required much
more attention. Malaysia was itself largely to blame for this as it failed to
raise this issue in its written submissions and left it to the closing state-
ments of its oral submissions. Nevertheless, it is an issue of vital impor-
 ance to the outcome of the case and one which warranted more consid-
eration than it received.

   15. Related to the question of the authority of the Acting State Sec-
retary of Johor to pronounce on matters of external affairs is the ques-
 ion of the nature of agreement, if it was an agreement at all, between
Singapore and Johor arising from the 1953 correspondence. Was it a
 reaty governed by international law ? Although the Sultan of Johor may
have been an independent sovereign, Johor was not a fully independent
State but a protectorate (and consequently not a Member of the United
Nations). This probably explains why no attempt was made to register
 he “agreement” under Article 102 of the United Nations Charter. But
what was the status of agreements between two British dependencies ?
Were they agreements inter se (like the agreements between the former
Dominions within the British Commonwealth) ? If they were, it is not
“easy”, in the words of Lord McNair, “to give a simple answer” to the
question whether such agreements were “governed by international law
or by some domestic system of law” (Lord McNair, The Law of Treaties,

130

1961, p. 115). And if the 1953 correspondence was not governed by inter-
national law does this affect the consequences to be attached to it ?

   16. Another question, also related to the authority of the Acting State
Secretary, is whether he had the authority to dispose of territory that ulti-
mately fell under the British Crown ? If he had the authority to dispose of
Pedra Branca/Pulau Batu Puteh by a note that was relegated by its recipi-
ent to its archives, would he have had the authority to settle a boundary
dispute or to dispose of a large section of the Johor mainland ? Or would
 his have constituted an “external affair” to be determined by the British
Crown ?
   17. Fifthly, why did Singapore not publicize the fact that Johor/Mal-
aysia had conceded that “ownership” (sovereignty) over Pedra Branca/
Pulau Batu Puteh vested in Singapore ? If the 1953 letter was as signifi-
cant as Singapore claims, it remains a mystery as to why this matter was
not given publicity beyond the bureaucracy of Singapore. Why did Sing-
apore not fly its national flag over the island, place it on its own maps,
publish it in its promotional brochures ? Register it under Article 102 of
 he United Nations Charter ? If the purpose of the letter of enquiry was
 o determine the boundaries of Singapore’s territorial waters why did
Singapore not publicly proclaim its maritime boundaries after 1953 ? The
answer provided by the Court that this could have led to claims for ter-
ritorial waters by neighbouring States that might interfere with the rights
of Singapore fishermen is both speculative and unconvincing.

   18. At the beginning of its Judgment the Court asserts that “[i]t is a
general principle of law, confirmed by the jurisprudence of this Court,
 hat a party which advances a point of fact in support of its claim must
establish that fact” (Judgment, para. 45). Later it adds that :
      “any passing of sovereignty over territory on the basis of the con-
      duct of the Parties . . . must be manifested clearly and without any
      doubt by that conduct and the relevant facts. That is especially so if
      what may be involved, in the case of one of the Parties, is in effect
      the abandonment of sovereignty over part of its territory.” (ibid.,
      para. 122.)
The question whether Singapore discharged the burden of proof cannot
arise in respect of the consequences of the 1953 correspondence as Sing-
apore attached very different consequences to the correspondence to
 hose attached to the correspondence by the Court. Whereas the Court
views the correspondence as a “tacit” agreement (ibid., para. 120) or
 he culmination of a “developing understanding” (ibid., paras. 203, 223,

131

230, 276) that Johor did not claim sovereignty over the island, or had
acquiesced in Singapore’s sovereignty over the island, Singapore denied
 hat it was part of its argument that Johor had renounced or abandoned
 itle over Pedra Branca/Pulau Batu Puteh for “the simple reason” that it
had no title to renounce or abandon (written response of Singapore to
 he question put by Judge Keith dated 30 November 2007). As the Court
has drawn different conclusions from the 1953 correspondence from
 hose advanced by Singapore, the Court must be satisfied that Johor’s
conduct “manifested clearly and without any doubt” that it had in effect
abandoned sovereignty over the island. Whether the 1953 correspond-
ence provides such evidence is highly doubtful in the light of the very real
uncertainties relating to the meaning, nature and consequences of this
correspondence.

   19. The Court understandably has difficulty in finding a clear legal
basis for its finding that the 1953 correspondence substantially contrib-
uted to the transfer of sovereignty from Johor to Singapore. It rightly
holds that the correspondence was not constitutive and did not create
 itle, that the letter from the Acting State Secretary did not constitute a
binding unilateral undertaking and that no estoppel arose. However, the
Judgment does not indicate clearly what conclusions are to be drawn
 rom the 1953 correspondence. In the sections of the Judgment associated
with the 1953 correspondence, the Court states that the “correspondence
and its interpretation are of central importance for determining the devel-
oping understanding of the two Parties about sovereignty over Pedra
Branca/Pulau Batu Puteh” (Judgment, para. 203) ; “that Johor’s reply
shows that as of 1953 Johor understood that it did not have sovereignty
over Pedra Branca/Pulau Batu Puteh” ; and that “[i]n light of Johor’s
reply, the authorities in Singapore had no reason to doubt that the
United Kingdom had sovereignty over the island” (ibid., para. 223 ; see
also para. 230). It also talks of an “evolving understanding shared by the
Parties” (ibid., para. 224). Earlier in the Judgment the Court comments,
probably with reference to the 1953 correspondence, that the passing of
sovereignty may result from a “tacit” agreement arising from the conduct
of the Parties (ibid., para. 120) and from the failure of a State which has
sovereignty to respond to the conduct of the other State à titre de sou-
verain, in which case the “absence of reaction may well amount to acqui-
escence” (ibid., para. 121). Acquiescence, in this context, says the Court,
 s “equivalent to tacit recognition manifested by unilateral conduct which
 he other party may interpret as consent” (ibid. ; citing the Delimitation
of the Maritime Boundary in the Gulf of Maine Area (Canada/United
States of America), Judgment, I.C.J. Reports 1984, p. 305, para. 130).
Later, in its concluding section of the Judgment, with reference in part to
 he 1953 correspondence — described as being of “major significance” in
 he Court’s assessment of the situation (Judgment, para. 275) — the
Court declares that the relevant facts, including the conduct of the
Parties “reflect a convergent evolution of the positions of the Parties

132

regarding title to Pedra Branca/Pulau Batu Puteh” resulting in the pass-
 ng of sovereignty over the island to Singapore (Judgment, para. 276).
From this it appears that notions of tacit agreement, developing or evolv-
 ng understanding (a synonym for tacit agreement ?) and acquiescence,
evidenced by the conduct of the Parties, provide the legal basis for the
Court’s Judgment. Clearly, Johor’s letter of 1953 features prominently in
 he Court’s assessment. Whether tacit agreement based on: the conduct
of parties, a “developing understanding” that sovereignty had passed, or
acquiescence, in the context of the facts of the case, as for it providing a
sound legal basis for the passing of sovereignty will be examined later.

                         THE PERIOD 1953 TO 1980

   20. The Court’s approach to the legal consequences to be attached to
 he events of the period 1953 to 1980 are premised on and influenced by
 ts finding that Johor (Malaysia) had acknowledged the sovereignty of
Singapore over Pedra Branca/Pulau Batu Puteh in the 1953 letter from
 he Acting State Secretary of Johor. The actions of Singapore thereafter
are positively interpreted to support its claim to sovereignty while its fail-
ures to act — its omissions — are excused. Conversely, no positive legal
significance is attached to Malaysia’s actions, while its failures to act are
seen as further evidence of its acquiescence in Singapore’s claim. This is
evidenced by an examination of the Court’s Judgment.

   21. The Court finds that Singapore’s investigation of shipwrecks in the
vicinity of Pedra Branca/Pulau Batu Puteh has favourable legal conse-
quences for Singapore despite the fact that Singapore as lighthouse
operator was obliged to do so. It holds that Singapore’s exercise of con-
 rol over official visits (including by Malaysia) to the island weighed in
Singapore’s favour, and declines to view Malaysia’s acquiescence in this
practice as polite deference to the authority of its lessee. Singapore’s
 nstallation of military equipment on the island is counted in its favour
despite Malaysia’s uncontested assertion that it was unaware of this fact
and therefore unable to react. So too is Singapore’s proposal to extend
 he island by reclamation, which again was done without Malaysia’s
knowledge. On the other hand, no adverse inference is drawn from the
 ailure of Singapore to protest, express concern or even publicly take
notice of a number of open actions by Malaysia in the vicinity of Pedra
Branca/Pulau Batu Puteh which had potentially serious implications for
 t — the 1968 Petroleum Agreement between Malaysia and the Continen-
 al Oil Company of Malaysia, the 1969 Malaysian Territorial Seas legis-
 ation extending Malaysia’s territorial waters, and the Agreements of

133

1969/1970 between Malaysia and Indonesia delimiting their continental
shelf and territorial waters. Surprisingly, the Court fails to attach any sig-
nificance to the failure of the 1973 Territorial Sea Agreement between
Singapore and Indonesia to include any mention of Pedra Branca/Pulau
Batu Puteh. Generously, the Court likewise draws no adverse inference
 rom the failure of Singapore’s official publications to include the island
as Singaporean territory, and dismisses as insignificant an assertion made
 n 1966 by J. A. L. Pavitt, for many years Director of Marine in Singa-
pore, that Pedra Branca/Pulau Batu Puteh did not belong to Singapore
 J. A. L. Pavitt, The First Pharos of the Eastern Seas : Horsburgh Light-
house). On the other hand, the Court considers as “significant” the fact
 hat Malaysia listed Horsburgh lighthouse as a “Singapore Station” in
 wo meteorological reports. Malaysia’s explanation that this simply meant
 hat this was a Singapore rainfall station is discounted. Finally the Court
notes, in passing, and without comment, that Singapore did not include
Pedra Branca/Pulau Batu Puteh as part of Singapore in any map it pub-
 ished between 1847 and 1995.

   22. The Court is ambivalent in its treatment of Singapore’s flying of
 he ensign over Pedra Branca/Pulau Batu Puteh rather than its national
flag. It acknowledges that the flying of an ensign “is not in the usual case
a manifestation of sovereignty” (Judgment, para. 246), but draws an
 nference adverse to Malaysia from its failure to protest about the flying
of the ensign over the uninhabited island of Pedra Branca/Pulau Batu
Puteh when it had protested over the flying of the ensign over the larger
and inhabited island of Pulau Pisang. In my view, the Court should
 nstead have drawn an inference adverse to Singapore for its failure to fly
 ts national flag over Pedra Branca/Pulau Batu Puteh. This failure speaks
volumes as it indicates clearly that Singapore did not at any time believe
 or at least had no confidence in such a belief) that it enjoyed sovereignty
over the island and that for this reason it was unprepared to engage in a
public display of alleged sovereignty that would inevitably have followed
 rom the flying of the national flag.

   23. Malaysia’s actions are viewed less positively. The fact that the
Malaysian and Singaporean navies together patrolled the seas in the
vicinity of Pedra Branca/Pulau Batu Puteh is treated as insignificant. No
weight is given to a 1968 letter of the Chief of the Malaysian Navy
declaring that the territorial waters of Pedra Branca/Pulau Batu Puteh
were part of Malaysia’s territorial sea on the ground that this letter was
not made public. (This might have been an acceptable argument had the

134

Court not been more generous in its attachment of significance to Singa-
pore’s secret installation of military equipment and proposed land recla-
mation : see para. 21 above.) No legal consequences are attached to the
Government of Malaysia’s 1968 Petroleum Agreement with the Conti-
nental Oil Company of Malaysia authorizing the company to explore for
oil in the vicinity of Pedra Branca/Pulau Batu Puteh. Here the Court
might well have taken judicial notice of the sensitivity displayed by States
 n respect of exploration for oil and that this Agreement must have
received the attention of Singapore — resulting in an expectation of some
response. No weight is given to Malaysia’s 1969 legislation on its territo-
rial sea on the ground that it does not expressly mention Pedra Branca/
Pulau Batu Puteh. Again, one would surely have expected a State with an
unpublicized claim to territory in the region to at least have reminded
Malaysia of its interest. Malaysia’s agreements with Indonesia over their
continental shelf and territorial seas are treated in a similar vein, and no
adverse inference is drawn from Singapore’s silence, despite its obvious
 nterest in respect of territorial claims in the region.

   24. The Court’s handling of the maps depicting Pedra Branca/Pulau
Batu Puteh is highly unsatisfactory. The Court attaches considerable sig-
nificance to six Malaysian maps that appear to describe Pedra Branca/
Pulau Batu Puteh as Singaporean territory, without seriously considering
Malaysia’s highly plausible explanation that “Singapore” in context
referred to the Horsburgh lighthouse only and not to the island. (At this
stage the Court might also have considered the question whether Singa-
pore’s decision to fly the ensign rather than its national flag gave any sup-
port to Malaysia’s explanation.) On the other hand, the Court dismisses
 hose maps which clearly support Malaysia’s position. First, it doubts the
significance of three maps published in 1926 and 1932 by the Surveyor-
General of the Federated Malay States and Straits Settlements, which
 ndicate clearly (despite the Court’s statement that they “may” indicate)
 hat the island is within Johor. Secondly, it even fails to consider other
maps produced by Johor and the United Kingdom, which place Pedra
Branca/Pulau Batu Puteh within Malaysian territory.

                      OVERALL FACTUAL ASSESSMENT

  25. This case involves a dispute between two friendly nations, both for
many years subject to British authority or influence, whose friendship
and close constitutional relationship is in part the reason for the present
dispute. This friendship has allowed the issue of sovereignty over Pedra
Branca/Pulau Batu Puteh to go virtually unnoticed for 130 years. In

135

approaching the dispute it is essential to have regard to these historical
and political circumstances.
   26. Before 1980 no serious attention was paid to the status of Pedra
Branca/Pulau Batu Puteh. Malaysia thought the island belonged to it.
Singapore too, at some time after the construction of the Horsburgh
 ighthouse, thought it belonged to it. But, wisely, both Parties allowed the
overriding interest of safety of navigation in the Singapore Straits to pre-
vail over territorial claims. The 1953 correspondence did not disturb the
relationship between the Parties. Having been informed by Johor that it
did not claim “ownership” (whatever this may mean) over Pedra Branca/
Pulau Batu Puteh, Singapore did nothing to advertise this information to
 hird States. It did not take any actions based on this information itself.
Instead both Parties relegated this information to their archives. Maybe
 hey did this to avoid maritime disputes in the region in the wake of the
“new” Law of the Sea declared in the Fisheries case (United Kingdom v.
Norway) (Judgment, I.C.J. Reports 1951, p. 116). Maybe Singapore did
not wish to disturb its good relationship with Johor by a request for clari-
fication of the 1953 letter by the Acting State Secretary. Whatever the
reason for this conduct, or lack of conduct, nothing was done and the
Parties continued as they had behaved before 1953.

   27. Singapore continued to behave as a lighthouse operator unac-
countable to Malaysia. It was careful not to flaunt its sovereignty, if it
believed that it was sovereign. It did nothing to advertise that it consid-
ered itself to be sovereign. It flew the ensign over the island rather than its
national flag. It accepted Malaysian naval patrols in the vicinity of the
 sland. Military communication equipment was quietly installed on the
 sland. Land reclamation plans were not proceeded with. Official publi-
cations made no attempt to include the island in Singaporean territory.
Singapore published no map claiming the island as its own. It refrained
 rom reminding Malaysia that it had an interest in the continental shelf
or territorial sea of the island when Malaysia entered into a petroleum
agreement (1968), adopted legislation on its territorial sea (1969) and
entered into an agreement with Indonesia in respect of continental shelf
and territorial sea. It raised no objections to maps that included Pedra
Branca/Pulau Batu Puteh in Malaysian territory. And, finally, it refrained
 rom claiming the island in its 1973 Territorial Sea Agreement with
Indonesia.

   28. Malaysia likewise continued to behave as a lessor without any
expectation of accountability from its lessee. It failed to protest Singa-
pore’s activities on the island, even when they went beyond those of a
 ighthouse operator. It accepted that it was required to obtain permission
 rom its lessee for visits to the island. It raised no objections to the Sing-
apore navy patrolling the vicinity of the island. It failed to object to Sing-

136

apore’s flying of the ensign, despite the fact that it objected to such con-
duct in the case of Pulau Pisang. It acknowledged that Singapore
controlled the island in its six notorious maps. On the other hand, in a
rare display of sovereignty, it did not consult Singapore when it entered
 nto a petroleum agreement for the continental shelf, enacted legislation
 or its territorial sea and entered into an agreement with Indonesia for
 he delimitation of its continental shelf and territorial sea.

  29. It was not until 1980 that the Parties realized that they had a dis-
pute on their hands. But even then they continued to behave amicably
 owards each other. Both claimed original title to the island and Singa-
pore politely refrained from claiming that it had acquired title by pre-
scription, possibly because it did not wish to suggest that it had for many
years been an adverse possessor of the island.

                             LEGAL ASSESSMENT
   30. As I have said in paragraph 2, I find it difficult to fully understand
 he basis for the Court’s Judgment. Notions of conduct, acquiescence,
 acit agreement and abandonment of title feature in the Court’s explana-
 ion for its decision (see Judgment, paras. 120-121, 162, 203, 223-224, 230
and 275). However, the Court fails to explain how sovereignty over Pedra
Branca/Pulau Batu Puteh passed from Johor/Malaysia to Singapore in
 erms of traditional or accepted rules governing the acquisition of terri-
 orial title. In particular, it fails to address the question whether there was
“an intentional display of power and authority” over Pedra Branca/Pulau
Batu Puteh on the part of Singapore “by the exercise of jurisdiction and
State functions, on a continuous and peaceful basis” — a formula said to
reflect the “modern international law on the acquisition (or attribution)
of territory” by the Tribunal in the Eritrea/Yemen Arbitration Award
 Territorial Sovereignty and Scope of the Dispute, Eritrea/Yemen (1998)
22 RIAA, pp. 209, 268, para. 239). In order to decide whether the Court’s
Judgment can be justified in law the wisest course seems to be to examine
 he decision within the framework of accepted, or at least known, grounds
normally advanced for the acquisition of territorial title and then to test
 he facts of the case against the grounds that appear to have been
advanced by the Court.

  31. On the face of it, Singapore’s claim looks very much like a claim
based on prescription. Malaysia has original title but Singapore claims
 hat for 130 years it has possessed the island and performed acts in
respect of the island à titre de souverain, peacefully and uninterruptedly.
But strangely, Singapore chose not to argue this. It repeatedly stated that
“the notion of prescription . . . has no role to play in the present case”
 CR 2007/22, p. 29, para. 69) and instead maintained that it :

137

      “relies on its conduct after 1851 not for purposes of establishing a
      legal title to the territory in dispute — that title was already estab-
      lished by 1851 — but rather to demonstrate that that title was main-
      tained and confirmed by a series of concrete activities on the ground
      which have lasted for over 150 years” (CR 2007/22, p. 28, para. 66).
Malaysia accepted that “the notion of prescription . . . has no role to play
 n the present case” (CR 2007/26, p. 35, para. 1).
   32. It is not known why Singapore chose not to pursue so obvious an
argument, even if only in the alternative. And, with the knowledge of
hindsight (although the Court must have realized from the outset it
would have to deal with some kind of prescription), it is unfortunate that
 he Court did not ask the Parties to address it on prescription.

   33. Prescription is a concept of uncertain content in international law.
According to R. Y. Jennings, it is “a portmanteau concept that compre-
hends both possession of which the origin is unclear or disputed, and an
adverse possession which is in origin demonstrably unlawful” (R. Y. Jen-
nings, The Acquisition of Territory in International Law (1963) p. 23). In
 he case concerning Kasikili/Sedudu Island (Botswana/Namibia) (Judg-
ment, I.C.J. Reports 1999 (II), p. 1103, para. 94 and p. 1105, para. 97),
 he Court accepted that for a claim based on prescription to succeed it
must be shown that possession is à titre de souverain, peaceful and un-
 nterrupted, public and endure for a certain length of time (see also,
D. H. N. Johnson, “Acquisitive Prescription in International Law”,
 1950) 27 British Year Book of International Law, pp. 344-348). Publicity
 s an essential requirement for prescription. According to Malcolm Shaw
 he possession must be public “so that all interested States can be made
aware of it” (International Law, 5th ed. 2003, p. 427). Judge Max Huber
was also keenly aware of this requirement in his decision in the Island of
Palmas Case (Netherlands/United States of America) (Award of
4 April 1928, RIAA, Vol. II (1949), pp. 839, 868), as he repeatedly
emphasized the need for a “continuous and peaceful display of State
authority” (emphasis added) in order to establish title. Given Singapore’s
 ailure to expressly and openly assert its claim to sovereignty over Pedra
Branca/Pulau Batu Puteh, and in particular its failure or refusal to pub-
 icize Johor’s response to its letter of 1953, it is highly unlikely that it
could have succeeded in a claim based on prescription — had it chosen to
argue this. In the event, the Court studiously avoided any suggestion that
 ts Judgment was based on prescription.

  34. Another ground, that was raised by Singapore and might have
been invoked by the Court for its decision, was estoppel — a term :
      “used to denote a legal principle which operates so as to preclude a
      party from denying before a tribunal the truth of a statement of fact

138

      made previously by that party to another whereby that other has
      acted to his detriment” (I. Sinclair “Estoppel and Acquiescence” in
      V. Lowe and M. Fitzmaurice (eds.), Fifty Years of the International
      Court of Justice: Essays in Honour of Sir Robert Jennings (1996),
      p. 105).

After all, estoppel and acquiescence are closely linked and acquiescence
 eatures in the Court’s Judgment. However, the Court rightly rejects
estoppel as the basis for the acquisition of title on the ground that there
was no evidence that Singapore had taken any action in reliance on
Johor’s letter of 1953.
   35. The Court also, rightly, dismisses any suggestion that the letter of
1953 might be interpreted as a cession of the island from Johor to Sing-
apore by finding that it did not have a “constitutive character in the sense
 hat it had a conclusive legal effect on Johor” (Judgment, para. 227). Sin-
gapore’s argument that the 1953 letter might amount to a binding un-
dertaking is likewise dismissed on the ground that Johor’s statement
“was not made in response to a claim made by Singapore or in the con-
 ext of a dispute between them”, but was simply a response to a request
 or information (ibid., para. 229). Historical consolidation of title was
not considered by either Singapore or the Court as a basis for the acquisi-
 ion of title, probably because of the doubts that have recently been cast
on this root of title by the Court in the case concerning Land and Mari-
 ime Boundary between Cameroon and Nigeria (Cameroon v. Nigeria :
Equatorial Guinea Intervening) (Judgment, I.C.J. Reports 2002, p. 352).

   36. This leaves tacit agreement, some sort of acquiescence in Singa-
pore’s title or abandonment of title as the basis for the Court’s Judgment.
Abandonment of title is mentioned by the Court as a possible effect of
 he conduct of the Parties (Judgment, para. 122), but is not raised as a
separate basis for the acquisition of title. This is a wise course as the
“actual examples of it are scarce” (G. Marston, “The British Acquisition
of the Nicobar Islands, 1869 : A Possible Example of Abandonment of
Territorial Sovereignty”, (1998) 69 British Year Book of International
Law, p. 262) and the intention to abandon title must be manifest. Johor’s
 etter of 1953 would not seem to satisfy this test.

   37. The Court employs different terminology to describe what it per-
ceives to be a “tacit agreement” between Johor/Malaysia and Singapore
on the passing of sovereignty over Pedra Branca/Pulau Batu Puteh. Early
 n the Judgment, probably with reference to the 1953 correspondence, the
Court warns that the passing of sovereignty may result from “tacit”
agreement arising from the conduct of the Parties (Judgment, para. 120).
Later it talks about “evolving views” (ibid., para. 162) and an “evolving
understanding shared by the Parties” (ibid., para. 224). In its con-
cluding remarks on sovereignty over Pedra Branca/Pulau Batu Puteh, the

139

Court declares, in part with reference to the 1953 correspondence, that
 he relevant facts and conduct of the Parties “reflect a convergent evolu-
 ion of the positions of the Parties regarding title to Pedra Branca/Pulau
Batu Puteh” resulting in the passing of sovereignty over the island (Judg-
ment, para. 276). The “evolving understanding” between the Parties and
 he “convergent evolution” of their positions resulting from their conduct
can be read as meaning nothing else but tacit agreement between the
Parties arising from their conduct.

   38. Implied or tacit agreements must be approached with great cau-
 ion. An informal agreement is a very different agreement from an
 mplied agreement. In the former case the intention of parties to enter
 nto an agreement and the terms of the agreement are clear. However,
 hey agree to dispense with the formalities sometimes required for a
 reaty or agreement (see Temple of Preah Vihear, Preliminary Objec-
 ions, Judgment, I.C.J. Reports 1961, p. 31). In the latter case both inten-
 ion and terms of the agreement are inferred from the conduct of parties.
This does not mean that there should be any relaxation in respect of the
 undamental requirement for treaties or agreements, that is, that there
should be a concurrence of wills or a meeting of minds on the part of
both parties. This is because a tacit agreement remains an agreement,
although not covered by the limited definition of a treaty contained in
Article 2 (a) of the Vienna Convention on the Law of Treaties. Whereas
evidence of a treaty governed by the Vienna Convention on the Law of
Treaties is provided by its written form, a tacit agreement must be proved
by the conduct of parties, and here evidence will be less clear. Conse-
quently, the intention of parties must be manifestly clear ; their conduct
 hat constitutes the agreement must leave no room for doubt. Inevitably
 acit agreements are difficult to establish. This probably explains why,
despite mention of such agreements in Article 3 (b) of the Vienna Con-
vention on the Law of Treaties (whose Commentary makes specific men-
 ion of “tacit agreement”), few treatises deal with tacit agreements. It also
explains why there is very little State practice on tacit agreements and
why courts have treated such agreements with great caution. For instance,
 n the case concerning Rights of Nationals of the United States of
America in Morocco (Judgment, I.C.J. Reports 1952, p. 176), the Court
rejected an argument that “prolonged conduct”, in the form of “usage
and sufferance”, on the part of the Parties could constitute a binding
agreement (ibid., pp. 200-202, read with the joint dissenting opinion,
pp. 219-220).

   39. The existence of a tacit agreement must therefore be firmly estab-
 ished. This is acknowledged by the Court when it says that “any passing
of sovereignty over territory on the basis of the conduct of the Parties
  . . must be manifested clearly and without any doubt by that conduct
and the relevant facts” (Judgment, para. 122). This accords with the basic
rule that restrictions on States are not to be presumed (case concerning

140

 he S.S. “Lotus”, “Lotus”, Judgment No. 9, 1927, P.C.I.J., Series A,
No. 10, p. 18). Judged by these principles, I find it difficult to accept that
 he 1953 correspondence, riddled as it is with uncertainties and ambigui-
 ies (see above paragraphs 8-19), or the equivocal conduct of the Parties
 n the period 1953 to 1980 (see above paragraphs 20-28), can be held to
constitute a tacit agreement or understanding.

   40. Sovereignty over territory may pass, says the Court, as a result of
“the failure of the State which has sovereignty to respond to conduct à
 itre de souverain of the other State” (Judgment, para. 121). In such a
case, continues the Court, “[t]he absence of reaction may well amount to
acquiescence” (ibid.), which, in the words of the Court in Delimitation of
 he Maritime Boundary in the Gulf of Maine Area (Canada/United
States of America) (Judgment, I.C.J. Reports 1984, p. 305, para. 130) “is
equivalent to tacit recognition manifested by unilateral conduct which
 he other party may interpret as consent”. The Court does not again
expressly mention acquiescence in respect of the passing of sovereignty
over Pedra Branca/Pulau Batu Puteh, but prefers to rely on the evolution
of an understanding between the Parties, amounting to tacit agreement,
as a basis for its decision. Despite this, it seems that acquiescence features
as an element of the Court’s decision.

   41. In most situations acquiescence is linked to estoppel or prescrip-
 ion, but in this case it is connected instead to tacit agreement, in much
 he same way that was done by the Court in Land, Island and Maritime
Frontier Dispute (El Salvador/Honduras : Nicaragua intervening) (Judg-
ment, I.C.J. Reports 1992, p. 577, para. 364). Like tacit agreement,
acquiescence must be strictly interpreted. According to I. C. MacGib-
bon :
        “The purpose of insisting on circumspection in inferring the con-
      sent of a State from its inaction is to ensure that such acquiescence
      corresponds accurately with the implied intention of the acquiescing
      State, and to limit the benefits of acquiescence to claims which have
      been formulated in such a way that the acquiescing State has or
      ought to have knowledge of them.” (I. C. MacGibbon, “The Scope
      of Acquiescence in International Law” (1954) 31 British Year Book
      of International Law, p. 169.)

As shown above (paragraphs 8-18), so much uncertainty surrounds the
1953 correspondence that it is impossible to state that the claim in which
Johor/Malaysia is said to have acquiesced, has been sufficiently clearly
 ormulated to find that it had or ought to have had knowledge of the
claim now asserted by Singapore. Moreover, it is difficult to maintain
 hat Malaysia has acquiesced in a claim that is founded on a letter that
was carefully and deliberately concealed from the public eye by Singa-
pore between 1953 and 1980. Acquiescence surely requires consistency of

141

conduct on the part of the acquiescing State in respect of the asserted
claim. However one interprets the facts between 1953 and 1980 (see para-
graphs 20-28 above), it is impossible to argue that they display consistent
acquiescent conduct on the part of Malaysia. They are, to put it mildly,
equivocal. Some of Malaysia’s actions may be interpreted as acquies-
cence in Singapore’s claim — notably the 1953 letter and the six maps
 hat describe the island (or the lighthouse upon it ?) as belonging to Sing-
apore. But, as has been shown above, there are explanations for Malay-
sia’s conduct that allow its actions to be interpreted as non-acquiescent
acts. Moreover, there are actions that run counter to acquiescence, such
as the 1968 Petroleum Agreement, the 1969 Territorial Sea legislation
and Malaysia’s agreements of 1969 and 1970 with Indonesia over the
continental shelf and territorial sea, and the inclusion of Pedra Branca/
Pulau Batu Puteh within Malaysian territory in some maps. Had Singa-
pore advertised the letter of 1953 and had Malaysia failed to respond this
would have been a basis for a finding of acquiescence. But, of course,
Singapore failed to do so. Subject to minor lapses, the acts of Malaysia
 herefore are consistent with the behaviour of a State that believed it had
given permission to a State to operate a lighthouse on its island to con-
 inue operating the lighthouse. It is, in these circumstances, impossible to
 nfer acquiescence on the part of Malaysia in Singapore’s claim to sov-
ereignty over Pedra Branca/Pulau Batu Puteh.

   42. In 1998 the Tribunal in the Eritrea/Yemen Arbitration Award
stated :
        “The modern international law of the acquisition (or attribution)
      of territory generally requires that there be : an intentional display of
      power and authority over the territory, by the exercise of jurisdiction
      and state functions, on a continuous and peaceful basis.” (Terri-
      torial Sovereignty and Scope of the Dispute, Eritrea/Yemen, (1998)
      22 RIAA, p. 209, para. 239).)

This formulation requires serious attention for two reasons. First, because
 t gives effect to the jurisprudence of contemporary international law
 rom the time of Max Huber’s seminal decision in the Island of Palmas
Case (Netherlands/United States of America) (Award of 4 April 1928,
RIAA, Vol. II (1949), pp. 839, 868). Secondly, because it was expounded
by a Tribunal comprising two former Presidents of the International
Court of Justice (Professor Sir Robert Y. Jennings and Judge
Stephen M. Schwebel), the President of the Court (Judge Rosalyn Hig-
gins) and two highly experienced and well regarded international law
practitioners (Dr. Ahmed Sadek El-Kosheri and Mr. Keith Highet). In

142

my view, this is a formulation of the law on the acquisition of territory
 hat is to govern all acquisitions of territorial title based on the effective
control of territory over a long period of time, including prescription,
estoppel, abandonment of title by the previous sovereign, acquiescence
and tacit agreement evidenced by conduct. In other words, for the
grounds advanced by the Court in the present case — evolving under-
standing, tacit agreement or acquiescence evidenced by conduct — to sat-
 sfy the requirements of the law, they must be shown to result in a situa-
 ion in which there is an intentional display of power and authority over
Pedra Branca/Pulau Batu Puteh on the part of Singapore, by the exercise
of State functions, on a continuous and peaceful basis. For a State to
demonstrate an intentional display of power and authority it is not suf-
ficient that it has the intention to act as sovereign. In addition it must
display this intention publicly so that both the former, displaced sover-
eign and third States in the region are aware of the claim. In the light of
 he uncertainties surrounding the letter of 1953, the failure of Singapore
 o give publicity to Johor’s alleged disclaimer of sovereignty, and the
equivocal behaviour of both States in the period 1953 to 1980, it is
 mpossible to seriously argue that Singapore intentionally displayed power
and authority over the territory by the exercise of jurisdiction and State
 unctions. After all, as the Court accepts, many, perhaps most, of Singa-
pore’s actions were fully consistent with the actions of a lighthouse
keeper operating in terms of a perpetual lease or grant. Certainly, if Sing-
apore did intend to display power and authority over the island, it did so
 n a secretive manner without revealing these intentions to the outside
world, including Malaysia. The 1953 letter was not published, territorial
waters were not claimed around the island, the ensign rather than the
national flag was flown, official maps and publications did not claim the
 sland, military equipment was secretly installed and land reclamation
plans were not publicized and later withdrawn. To aggravate matters,
Singapore expressed no interest whatsoever in Malaysia’s plans to exploit
 he continental shelf and to claim the seas in the vicinity of the island. To
repeat, there was no intentional display of power and authority over the
 sland for third States and Malaysia to see. Singapore did exercise juris-
diction on a continuous and peaceful basis, but it did so as lighthouse
operator and not as a sovereign intentionally displaying power and
authority over the island.

  43. In my view, for the reasons advanced above, neither the facts nor
he law support the conclusion that sovereignty over Pedra Branca/Pulau
Batu Puteh has passed to Singapore. I therefore find that the original title
n respect of the island remains with Malaysia.
  44. I am of the opinion that both Middle Rocks and South Ledge fall
within the sovereignty of Malaysia. Malaysia’s title to Middle Rocks is

143

based on the original title. South Ledge, a low-tide elevation falling
within the territorial sea of Middle Rocks, belongs to Malaysia.
   45. The Court is not bound, in reaching its decision, by the submis-
sions of counsel representing parties before the Court. It may invoke rea-
sons of its own proprio motu when it considers that there is a sounder
basis for decision than that advanced by parties. In the present case the
Parties did not directly make submissions or present arguments on the
reasons adopted by the Court for the passing of sovereignty — tacit
agreement, evolving understanding and acquiescence evidenced by the
conduct of the Parties. The main reason for this was that Singapore
argued that Pedra Branca/Pulau Batu Puteh was terra nullius in 1847,
which largely precluded arguments based on control of the island and the
conduct of Parties. Nevertheless, as the Court points out in paragraph
124, the Parties did canvas related issues. Despite this, it would have been
helpful to the Court if the Parties had made submissions and presented
arguments on the legal reasons later approved by the Court. Unfortu-
nately, probably because it is not the practice of the Court to question
parties unduly or to interfere in their presentation of argument, no
attempt was made to solicit the views of the Parties on the reasons
advanced by the Court for its present Judgment. Justice was not neces-
sarily served by the failure of the Court to give some indication to the
Parties on the issues that it believed to be of paramount importance.

                                               (Signed) John DUGARD.

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