Case Concerning the Temple of Preah Vihear (Cambodia v.
Thailand)Author(s): Covey OliverSource: The American Journal of
International Law, Vol. 56, No. 4 (Oct., 1962), pp.
1033-1053Published by: American Society of International LawStable
URL: http://www.jstor.org/stable/2195943 .Accessed: 22/03/2011
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International Law is collaborating with JSTOR to digitize, preserve
and extend access toThe American Journal of International
Law.http://www.jstor.orgJUDICIALDECISIONS BY COVEYOLIVER Of the
Board of Editors Territorialtsovereignty-treaty
interpretation-maps-preclusion or estoppel
CASECONCERNINGTHETEMPLEOFPREAHVIHEAR(CAMBODIAV.
THAILAND),MERITS.I.C.J. Reports,1962, p. 6.1 InternationalCourt of
Justice.2 Judgmentof June 15, 1962. In its Judgmentof 26 May 1961,
by which it upheld its jurisdictionto adjudicate upon the dispute
submittedto it by the Application filedby the Governmentof Cambodia
on 6 October 1959, the Court described in the followingterms the
subject of the dispute: "Inthe present case, Cambodia alleges a
violation on the part of Thailand of Cambodia's
territorialsovereigntyover the region of the Temple of Preah Vihear
and its precincts.Thailand replies by af- firmingthat the area in
question lies on the Thai side of the common frontierbetween the
two countries,and is under the sovereigntyof Thailand.This is a
dispute about territorialsovereignty." Accordingly,the subject of
the dispute submittedto the Court is confined to adifferenceof view
about sovereigntyover the region of the Temple of Preah Vihear.To
decide this question of territorialsovereignty,the Court must have
regard to the frontierline betweenthe two States in this
sector.Maps have been-submittedto it and various considerationshave
been advanced in this connection. The Court will have regard to
each of these only to such extentas it may findin themreasons for
the decision it has to give in order to settle the sole dispute
submittedto it, the subject of which has just been stated. The
Temple of Preah Vihear is an ancient sanctuaryand shrinesituated on
the borders of Thailand andCambodia.Although now partially in
ruins,this Temple has considerableartisticand
archaeologicalinterest,and is still used as aplace of pilgrimage.It
stands on a promontoryof the same name, belongingto the eastern
sector of the Dangrek range of moun- tains which,in ageneral way,
constitutesthe boundary between the two countriesin this
region-Cambodia to the south and Thailand to the north.
Considerableportions of this range consist of a high
cliff-likeescarpment rising abruptlyabove the Cambodian plain.This
is the situationat Preah I Excerptedtext of opinionpreparedby Wm.
W. Bishop, Jr. 2 Composedfor this case of PresidentWiniarski;Vice
PresidentAlfaro; and Judges Basdevant,Badawi,
MorenoQuintana,WellingtonKoo, Sir Percy Spender,Sir Gerald
Fitzmaurice,Koretsky,Tanaka, Bustamantey Rivero,and Morelli. 1033
1034THEAMERICANJOURNALOFINTERNATIONALLAW[Vol. 56 Vihear
itself,wherethe main Temple buildings stand in the apex of a tri-
angular piece of high ground jutting out into the plain.From the
edge of the escarpment,the general inclinationof the ground in the
northerlydi- rectionis downwardsto the Nam Moun river,which is in
Thailand. It will be apparent fromthe descriptionjust given that a
frontierline whichran along the edge of the escarpment,or whichat
any rate ran to the south and east of the Temple area, would leave
this areain Thailand; whereas a line runningto the north,or to the
northand west,would place it in Cambodia. Thailand has urged that
the edge of this escarpmentconstitutesthe natu- ral and obvious
line for a frontierin this region.In support of this view Thailand
has referredto the documentaryevidence indicativeof the desire of
the Parties to establish frontierswhich would not only be
"natural", but visible and unmistakable-such as
rivers,mountainranges, and hence escarpments,wherethey exist. The
desire of the Parties for a natural and visible frontiercould have
been met by almostany line whichfolloweda recognizablecourse along
the main chain of the Dangrek range.It could have been a crestline,
a water- shed line or an escarpmentline (where an
escarpmentexisted,whichwas far fromalways being the case).As will
be seen presently,the Parties pro- vided for a watershedline.In so
doing, they must be presumed to have realized that such a line
would not necessarily,in any particular locality, be the same line
as the line of the crestor escarpment. They cannot there- fore be
presumedto have intended that, whereveran escarpmentexisted, the
frontiermustlie along it, irrespectiveof all otherconsiderations.
The Parties have also relied on otherargumentsof a
physical,historical, religious and archaeological character,but the
Court is unable to regard themas legally decisive. Asconcernsthe
burden of proof, it must be pointed out that though, fromthe
formalstandpoint,Cambodia is the plaintiff,having institutedthe
proceedings,Thailand also is aclaimant because of the claim which
was presentedby her in the second Submission of the
Counter-Memorialand which relates to the sovereigntyover the same
piece of territory. Both Cambodia and Thailand base
theirrespectiveclaims on a series of facts and contentionswhich are
asserted or put forwardby one Party or the other. The burden of
proof in respect of these will of course lie on the Party as-
sertingor putting them forward. Until Cambodia attained her
independence in1953 she waspart of French Indo-China, and her
foreign relations-like those of the rest of French Indo-China-were
conducted by France as the protectingPower. It is commonground
between the Parties that the present dispute has its fonset origoin
the boundary settlementsmade in the period 1904-1908, betweenFrance
and Siam (as Thailand was then called) and, in particular, that the
sovereigntyover Preah Vihear depends upon a boundary treaty dated
13 February 1904, and upon events subsequent to that date.The Court
is thereforenot called upon to go into the situation that existed
betweenthe Parties prior to the Treaty of 1904.
1962]JUDICIALDECISIONS1035 The relevantprovisionsof the Treaty of
13 February 1904, which regu- lated interalia the frontierin the
easternDangrek region,were as follows: [Translationrby the
Registry] "Article 1 The frontierbetweenSiam and Cambodia starts,on
the left shore of the Great Lake, fromthe mouth of the river Stung
Roluos, it follows the parallel fromthat point in an
easterlydirectionuntil it meets the river Prek Kompong Tiam, then,
turningnorthwards,it mergeswith the meridian from that
meeting-pointas far as the Pnom DangRek mountain chain.From there
it follows the watershed between the basins of the Nam Sen and the
Mekong,on the one hand, and the Nam Moun, on the otherhand, and
joins the Pnom Padang chain the crestof which it followseastwardsas
far as the Mekong. Upstreamfromthat point, the Mekong remains the
frontierof the Kingdom of Siam, in accordancewith Article 1 of the
Treaty of 3 October1893." "Article 3 There shall be a
delimitationof the frontiersbetweenthe Kingdom of Siam and the
territoriesmaking up French Indo-China.This de- limitationwill be
carried out by Mixed Commissionscomposedof offi- cers appointed by
the two contractingcountries. The work will relate to the
frontierdeterminedby Articles 1 and 2, and the region lying
betweenthe Great Lake and the sea." It will be seen, in the
firstplace, that these articles make no mentionof Preah Vihear as
such. It is for this reason that the Court can only give a decision
as to the sovereigntyover the Temple area after having examined
what the frontierline is.Secondly, whereas the general character of
the frontierestablishedby Article 1 was, along the Dangrek range,
to be a watershedline, the exact course of this frontierwas, by
virtue of Article 3, to bedelimited by aFranco-Siamese
MixedCommission. Itistobe observed,moreover,that what had to be
delimitedwas "the frontiers"be- tween Siam and French Indo-China;
and although this delimitationhad, prima facie, to be carried out
by referenceto the criterionindicated in Article 1, the purpose of
it was to establishthe actual line of the frontier. In
consequence,the line of the frontierwould, to all intentsand
purposes, be the line resultingfromthe work of delimitation,unless
the delimitation were shownto be invalid. Indue course, aMixed
Commissioncomposed of French and Siamese memberswas set up, charged
with the task of delimitingthe frontierin various
districts,including the eastern sector of the Dangrek range in
which Preah Vihear is situated.This Mixed Commissionwas composedof
two sections,one French and one Siamese, sittingtogether-one
consisting of French topographicaland administrativeofficersunder a
French presi- dent,and the otherof Siamese membersunder a Siamese
president. So far as the frontierin the Dangrek range was
concerned,the task of this Mixed Commissionwas confinedto the
easternsector (roughlyeast of the Pass of Kel)in whichPreah Vihear
is situated. At this time the westernsectorof the Dangrek lay
whollyin Thailand.It was only when a furtherboundary
settlement,under a treatydated 23 March 1907, broughtwithin
Cambodia 1036THEAMERICANJOURNALOFINTERNATIONALLAW[Vol. 56 various
districtsabutting on the western Dangrek sector,that the latter
became a frontierregion.The task of delimitingthe frontierin this
latter region was given to asecond Mixed Commissionset upunder the
1907 Treaty. The Mixed Commissionset up under the Treaty of 1904
held its first meetingin January1905, but did not reach that part
of its operationsthat concernedthe frontieralong the eastern sector
of the Dangrek range until December 1906, althoughit appears
fromthe minutesof the Commission's meetingof 2 December 1906 that
one of the French membersof the Com- mission,Captain Tixier, had
passed along the Dangrek in February 1905. At the meetingof 2
December1906, held at Angkor-Wat,it was agreed that the
Commissionshould ascend the Dangrek fromthe Cambodian plain by the
Pass of Kel, whichlies westwardsof Preah Vihear, and travel
eastwards along the range by the same route (or along the same
line)as had been reconnoitredby Captain Tixier in 1905 ("letrace
qu'areconnu . . . le capitaine Tixier").It was stated that all the
necessaryreconnaissancebe- tweenthis route and the crestline (to
which it ran roughlyparallel) could be carried out by this
method,since the route was, at the most,only ten to
fifteenkilometresfromthe crest,on the Siamese side.It has not been
con- tested that the Presidents of the French and Siamese
sectionsof the Com- mission,as representingit, duly made this
journey,and that in the course of it they visited the Temple of
Preah Vihear.But there is no record of any decision that they may
have taken. At this same meetingof 2 December 1906, it was also
agreed that an- other of the membersof the French section of the
Commission,Captain Oum, should, startingat the eastern end, survey
the whole of the eastern part of the Dangrek range, in which Preah
Vihear is situated,and that he would leave for this purpose the
next day. It is thus clear that the Mixed Commissionfully
intendedto delimitthe frontierin this sector of the Dangrek and
that it took all the necessary steps to put the work of
delimitationin hand.The work must have been accomplished,for at the
end of January 1907 the French Ministerat Bang- kok reportedto the
Ministerof Foreign Affairsin Paris that he had been
formallynotifiedby the Presidentof the French sectionof the Mixed
Com- missionthat the whole work of delimitationhad been
finishedwithoutinci- dent, and that the frontierline had been
definitelyestablished,except in the region of Siem
Reap.Furthermore,in a report on the whole work of
delimitation,dated 20 February 1907, destinedfor his own
Government,the Presidentsaid that: "Allalong the Dangrek and as far
as the Mekong,the fixingof the frontiercould not have involved any
difficulty." Mention may also be made of a map produced by
Thailand, recentlyprepared by the Royal ThaiSurvey Department,
Bangkok, tracing in the Dangrek the "Route followedby the Mixed
Commissionof 1904". It seems clear thereforethat a frontierwas
surveyedand fixed; but the question is what was that frontier(in
particular in the region of Preah Vihear), by whomwas it fixed,in
what way, and upon whose instructions? Tlhedifficultyin
answeringthese questions lies in the fact that, after the
1962]JUDICIALDECISIONS1037 minutesof the meetingof the First
Commissionon 2 December 1906, there is no
furtherreferencewhatever,in any minutesof later meetings,to the
question of the frontierin the Dangrek region. Itappears that at
about this time the Commissionhadin substance finishedits work on
the ground and was awaiting the reports and provi- sional maps of
the surveyofficers(Captain Oum and others).These reports and maps
would not be available until February-March1907 when,in nor- mal
circumstances,another meeting of the Commissionwould have been held
to considerthem.It appears that a meetinghad been provisionally
fixedfor 8 March.That it was certainlythe intentionto call one, can
be seen froma despatchfromthe French Ministerin Bangkok to the
Minister of Foreign Affairsin Paris, dated 23 February 1907,
coveringthe report fromColonel Bernard, President of the French
section of the Commission. The Minister,in his despatch,said:
"Themaps indicatingthe frontiercan be broughtup to date in a
fairlyshorttime and the plenarymeetingof the French and Siamese
Commissionerswill probablybe held before15 March." No
meetingapparentlyever took place.In the meantimethe two Govern-
ments had entered into negotiationsfor a furtherboundary
treaty.This treatywas signed on 23 March 1907, and provided for
exchanges of terri- toryand a comprehensiveregulationof all
thosefrontiersnot coveredby the previoustreatysettlementof 1904. A
second Mixed Commissionof Delimitationwas then set up under the
Treaty of 1907.As already mentioned,part of its task was to
delimitthat sectorof the Dangrek regionnot having come withinthe
ambit of the First Commission,namelyfromthe Pass of Kel
westwards,and thereforenot in- cluding Preah Vihear which lay to
the east.There was in fact some over- lapping of the workof the two
Commissionsin the Kel region,but this over- lapping did not
extendto Preah Vihear.There is, however,evidencein the recordsof
the Second Commissionthat,at or near the Pass of Kel, the line
drawn by this Commissionjoined up with an already existingline
proceed- ing eastwardsto the Temple area and beyond.There is no
definiteindica- tion as to what this line was, or how it had come
to be established; but the presumptionthat it was in some manneror
otherthe outcomeof the survey workwhichthe First Commissionhad put
in hand, and whichthe President of its French section,in his
reportof 20 February 1907, stated to have been accomplishedwithout
difficultyis, in the circumstances,overwhelmingly strong. The Court
has noted that although,under Article IV of the Treaty of 1907, the
task of the Second Mixed Commissionwas to delimitthe "new
frontiers" establishedby that Treaty, the Commissionalso had the
task, under Clause IIIof the Protocol attached to the Treaty, of
delimitingall that part of the frontierdefinedin Clause Iof the
Protocol.This latter provisionrelated to the entire Dangrek range
froma point in its western half to the eastern continuationof the
Dangrek, the Pnom Padang range, as far as the River Mekong.
Therefore,had the easternDangrek and Pnom Padang sectorsnot already
been delimitedby the first(1904)Mixed Com- mission,it would have
been the duty of the second (1907)Commissionto do this work.This
Commissiondid not do it, apart fromthe overlap (not
1038THEAMERICANJOURNALOFINTERNATIONALLAW[Vol. 56 extending to Preah
Vihear)already mentioned,andthereforethe pre- sumptionmustbe that
it had already been done. The First Mixed Commissionapparently did
not hold any formalmeet- ing after 19 January 1907.It must not be
forgottenthat, at the time when such a meetingmighthave been held
for the purpose of winding up the workof the Commission,attentionin
both countries,on the part of those who were specially qualifiedto
act and speak on their behalf in these mat- ters,was
directedtowards the conclusionof the Treaty of 23 March 1907. Their
chief concern,particularly in the case of Colonel Bernard, could
hardly have been the formal completionof the results of the
delimitation theyhad carried out. The finalstage of the operationof
delimitationwas the preparationand publicationof maps.For the
executionof this technicalwork,the Siamese Government,which at that
time did not dispose of adequate means, had officiallyrequested
that French topographical officersshould mapthe -frontierregion.It
is clear fromthe opening paragraph of the minutesof the meetingof
the First Mixed Commissionon 29 November1905 that this request had
the approval of the Siamese section of the Commission,which may
indeed have inspired it, for in the letter of 20 August 1908 in
which the Siamese Ministerin Paris communicatedto his Governmentthe
eventual resultsof this work of mapping,he referredto "the Mixed
Commissionof Delimitationof the frontiersand the Siamese
Commissioners'request that the French Commissionersprepare maps of
various frontiers". That this was the deliberatepolicy of the
Siamese authoritiesis also shown by the fact that in the Second
(1907)Mixed Commission,the French membersof the Commissionwere
equally requestedby theirSiamese colleaguesto carry out
cartographicalwork,as can be seen fromthe minutesof the meetingof 6
June 1908. The French Governmentduly arrangedforthe workto be done
by a team of four French officers,threeof whom,Captains
Tixier,Kerler and de Batz, had been membersof the First Mixed
Commission.This team workedunder the general directionof Colonel
Bernard, and in the late autumn of 1907 it completeda series of
eleven maps coveringa large part of the frontiersbe- tween Siam and
French Indo-China,including those portionsthat are ma- terial in
the present case.The maps were printed and published by a
well-knownFrench cartographicalfirm,H.Barrere. The eleven maps were
in due course communicatedto the Siamese Gov- ernment,as being the
maps requestedby the latter,and the Court will con- sider later the
circumstancesof that communicationand the deductionsto be drawn
fromit.Three of the maps had been overtakenby events,inas- much as
the formerfrontierareas theyshowedhad, by virtue of the Treaty of
March 1907, now become situated wholly in Cambodia.Siam was not
thereforecalled upon eitherto accept or reject them.Her interestin
the othermaps romained. Amongstthese was one of that part of the
Dangrek range in whichthe Temple is situated,and on it was traced a
frontierline purportingto be the outcomeof the work of
delimitationand showingthe whole Preah Vihear promontory,with the
Temple area, as being on the 1962]JUDICIALDECISIONS1039 Cambodian
side.If thereforethe delimitationcarried out in respectof the
easternDangrek sectorestablishedor was intendedto establisha
watershed line, this map purportedto show such a line.This map was
filedby Cam- bodia as Annex I to its Memorial,and has becomeknown
in the case (and will be referredto herein) as the Annex I map. It
is on thismap that Cambodia principallyrelies in supportof her
claim to sovereigntyover the Temple.Thailand, on the otherhand,
contestsany claim based on this map, on the followinggrounds:
first,that the map was not the workof the Mixed Commission,and had
thereforeno binding char- acter; secondly,that at Preah Vihear the
map embodieda material error, not explicableon the basis of any
exerciseof discretionarypowersof adapta- tion which the
Commissionmay have possessed.This error,according to Thailand's
contention,was that the frontierline indicated on the map was not
the true watershedline in this vicinity,and that a line drawn in
ac- cordance with the true watershedline would have placed, and
would now place, the Temple area in Thailand.It is
furthercontendedby Thailand that she never accepted this map or the
frontierline indicated on it, at any rate so far as Preah Vihear is
concerned,in such a way as to becomebound thereby; or,
alternativelythat, if she did accept the map, she did so only
under, and because of, a mistakenbelief (upon which she relied)
that the map line was correctlydrawn to correspondwith the
watershedline. The Court will, for the moment,confineitself to the
firstof these con- tentions,based on an argumentwhich the Court
considers to be correct, namelythat the map was never
formallyapproved by the First Mixed Com- missionas such, since that
Commissionhad ceased to functionsome months beforethe productionof
the map.The record does not show whetherthe map and the line were
based on any decisions or instructionsgiven by the Commissionto the
surveyingofficerswhile it was still functioning. What is certainis
that the map must have had a basis of some sort,and the Court
thinkstherecan be no reasonabledoubt that it was based on the work
of the surveyingofficersin the Dangrek sector. Being one of the
series of maps of the frontierareas produced by French
Governmenttopographicalexperts in responseto a request made by the
Siamese authorities,printed and pub- lished by a Paris firmof
repute,all of whichwas clear fromthe map itself, it was thus
investedwith an officialstanding; it had its own inherenttech-
nical authority;and its provenancewas open and obvious. The Court
must neverthelessconclude that, inits inception, andatthe moment of
its production,it had no binding character. Thailand has argued
that in the absence of any delimitationapproved and adopted by the
Mixed Commission,or based on its instructions,the line of the
frontiermust necessarily-by virtue of Article 1 of the Treaty of
1904 followstrictlythe line of the true watershed,and that this
line, at Preah Vihear, would place the Temple in Thailand.While
admittingthat the Mixed Commissionhad a certain discretionto depart
fromthe watershed line in orderto avoid anomalies,and to take
account of certainpurely local considerations,Thailandcontends that
any departure such asto place Preah Vihear in Cambodia would have
far exceeded the scope of any dis-
1040THEAMERICANJOURNALOFINTERNATIONALLAW[Vol. 56 cretionary powers
the Mixed Commissioncould have hadauthority to
exercisewithoutspecificreferenceto the Governments. Whatever
substance these contentionsmay have, taken by themselves, the Court
considers that they do not meet the real issues here involved. Even
if there was no delimitationof the frontierin the eastern sector of
the Dangrek approved and adopted by the Mixed Commission,it was ob-
viouslyopen to the Governmentsthemselvesto adopt a delimitationfor
that region,makinguse of the workof the technicalmembersof the
Mixed Com- mission. As regards any departures from the
watershedline which any such delimitationembodied-since,
accordingto Thailand's own contention, the delimitationindicated on
the Annex I map was not the Mixed Commis- sion's-there is no point
in discussingwhethersuch departuresas may have occurredat Preah
Vihear fell withinthe Commission'sdiscretionarypowers or not.The
point is that it was certainlywithinthe power of the Govern-
mentsto adopt such departures. The real question, therefore,which
is the essential one in this case, is whetherthe Parties did adopt
the Annex I map, and the line indicated on it, as representingthe
outcomeof the work of delimitationof the frontier in the regionof
Preah Vihear, therebyconferringon it a bindingcharacter. Thailand
denies this so far as she is concerned,representingherselfas having
adopted a merelypassive attitude in what ensued.She maintains also
that a course of conduct,involvingat most a failure to object,
cannot sufficeto render her aconsentingparty to adeparture at Preah
Vihear from the watershedline specifiedby Article 1 of the Treaty
of 1904, so great as to affectthe sovereigntyover the Temple area.
The Court sees the matterdifferently.It is clear from the record
that the publicationand communicationof the eleven maps referredto
earlier, including the Annex Imap, was somethingof an occasion.This
was no mere interchangebetween the French and Siamese
Governments,though, even if it had been,it could have sufficedin
law.On the contrary,the maps were given wide publicity in all
technicallyinterestedquarters by being also communicatedto the
leading geographicalsocietiesin importantcoun- tries, and to other
circles regionally interested; to the Siamese legations
accreditedto the British,German,Russian and United States
Governments; and to all the membersof the Mixed Commission,French
and Siamese.The full original distributionconsistedof about one
hundred and sixty sets of eleven maps each.Fifty sets of this
distributionwere allocated to the Siamese Government. That the
Annex Imap was communicatedas pur- portingto representthe outcomeof
the work of delimitationis clear from the letter fromthe Siamese
Minister in Paris to the Minister of Foreign Affairsin
Bangkok,dated 20 August 1908, in which he said that "regard- ing
the Mixed Commissionof Delimitationof the frontiersand the Siamese
Commissioners'request that the French Commissionersprepare maps of
various frontiers,the French Commissionershave now
finishedtheirwork". He added that a series of maps had been
broughtto him in order that he mightforwardthemto the Siamese
Ministerof Foreign Affairs. He went on to give a list of the eleven
maps, including the map of the Dangrek re-
1962]JUDICIALDECISIONS1041 gion-fifty sheets of each.Heended by
saying that he was keeping two sheets of each map for his Legation
and was sending one sheet of each to the Legations inLondon,
Berlin, Russiaandthe United States of America. It has been
contendedon behalf of Thailand that this communicationof the maps
by the French authoritieswas, so to speak, ex parte, and that no
formalacknowledgmentof it was eitherrequestedof, or given by,
Thailand. In fact, as will be seen presently,an acknowledgmentby
conduct was un- doubtedlymade in a very definiteway; but even if it
were otherwise,it is clear that the circumstanceswere such as
called for some reaction,withina reasonableperiod, on the part of
the Siamese authorities,if they wished to disagree with the map or
had any serious question to raise in regard to it. They did not do
so, either then or for many years, and therebymust be held to have
acquiesced.Qui tacet consentirevidetur si loqui debuqisset ac
potuisset. So far as the Annex I map is concerned,it was not
merelythe circum- stancesof the communicationof this and the
othermaps that called for some reactionfromthe Siamese side, if
reactiontherewas to be; therewere also indicationson the face of
the map sheet which required a reaction if the Siamese
authoritieshad any reason to contendthat the map did not repre-
sent the outcomeof the work of delimitation. The map-together with
the othermaps-was,as already stated, communicatedto the Siamese
members of the MixedCommission. Thesemust necessarily haveknown
(and throughthem the Siamese Governmentmust have known) that this
map could not have representedanythingformallyadopted by the Mixed
Com- mission,and thereforethey could not possibly have been
deceived by the title of the map, namely,"Dangrek-Commission of
Delimitationbetween Indo-China and Siam"into supposing that it was
purportingto be a pro- duction of the Mixed Commissionas
such.Alternatively,if the Siamese membersof the Commissiondid
suppose otherwise,this could only have been because,
thoughwithoutrecordingthem,the Mixed Commissionhad in fact taken
some decisionson whichthe map was based; and of any such decisions
the Siamese membersof the Commissionwould of course have been
aware. The Siamese membersof the Commissionmust also have seen the
notice appearing in the top left-handcorner of the map sheet to the
effectthat the workon the groundhad been carried out by Captains
Kerler and Oum. They would have known,since theywere presentat the
meetingof the Com- mission held on 2 December 1906, that Captain
Oum had then been in- structedto carryout the surveyof the
easternsectorof the Dangrek range, coveringPreah Vihear, and that
he was to leave the next day to take up this assignment. They said
nothing-either then or later-tosuggest that the map did not
representthe outcomeof the workof delimitationor that it was in any
way inaccurate. That the Siamese authoritiesby their
conductacknowledgedthe receipt, and recognizedthe character,of
these maps, and what they purportedto represent,is shown by the
action of the Minister of the Interior, Prince
1042THEAMERICANJOURNALOFINTERNATIONALLAW[Vol. 56 Damrong,in
thankingthe French Ministerin Bangkok for the maps, and in asking
him for anotherfifteencopies of each of themfor transmissionto the
Siamese provincialGovernors. Further evidenceis affordedby the
proceedingsof the subsequent Com- missionof Transcriptionwhich met
in Bangkok in March of the following year, 1909, and for some
monthsthereafter. This was amixed Franco- Siamese Commissionset up
by the Parties with the object of getting an officialSiamese
geographicalservice started,througha consolidationof all the work
of the two Mixed Commissionsof 1904 and 1907.A primaryaim was to
convertthe existingmaps into handy atlas form,and to give the
French and Siamese terms used in them their proper equivalents in
the other languages.No suggestionthat the Annex Imap or line was
un- acceptablewas made in the courseof the workof this Commission.
It was claimed on behalf of Thailand that the maps received
fromParis were onlyseen by minorofficialswho had no experiencein
cartography,and would know nothing about the Temple of Preah
Vihear.Indeed it was suggestedduringthe oral proceedingsthat no one
in Siam at that timeknew anythingabout the Temple or would be
troublingabout it. The Court cannot accept these
contentionseitheron the facts or the law. If the Siamese
authoritiesdid show these maps only to minorofficials,they clearly
acted at theirown risk,and the claim of Thailand could not, on the
internationalplane, derive any assistance fromthat fact.But the
history of the matter,as set out above, shows clearly that the maps
were seen by such personsas Prince Devawongse,the Foreign
Minister,Prince Damrong, the Ministerof the Interior,the Siamese
membersof the First Mixed Com- mission,the Siamese membersof the
Commissionof Transcription; and it must also be assumed that the
Annex Imap was seen by the Governorof Khukhan province,the Siamese
provinceadjoining the Preah Vihear region on the northernside, who
must have been amongstthose for whom extra copies were requested by
Prince Damrong.None of these persons was a minor official. Allor
most had local knowledge.Some must have had knowledgeof the Dangrek
region.It is clear fromthe documentationin the case that Prince
Damrong took a keen personal interestin the work of
delimitation,and had a profoundknowledgeof archaeologicalmonuments.
Itis not conceivable that the Governor of Khukhan province, of
which Preah Vihear formedpart up to the 1904 settlement,was
ignorant of its existence. Inany case this particular contentionof
Thailand's is decisively dis- proved by a documentdeposited by
Thailand herself,according to which the Temple was in 1899
"re-discovered" by the Siamese Prince Sanphasit, accompaniedby some
fifteento twentyofficialsand local dignitaries,includ- ing, it
seems, the then Governorand Deputy-Governorof Khukhan.It thus
appears that only nine years previous to the receipt of the Annex I
map by the Siamese authorities,aconsiderablenumber of persons
having high officialstanding in Siam knew of Preah Vihear. The
Court moreoverconsidersthat there is no legal foundationfor the
consequenceit is attemptedto deduce fromthe fact that no one in
Thailand at that timemay have knownof the importanceof the Temple
or have been 1962]JUDICIALDECISIONS 1043 troublingabout it.Frontier
rectificationscannot in law be claimed on the groundthat a
frontierarea has turnedout to have an importancenot known or
suspectedwhenthe frontierwas established. It followsfromthe
precedingfindingsthat the Siamese authoritiesin due
coursereceivedthe Annex I map and that theyaccepted it.Now,
however, it is contendedon behalf of Thailand, so far as the
disputed area of Preah Vihear is concerned,that an error was
committed,an error of whlichthe Siamese authoritieswere unaware at
the time when they accepted the map. It is an establishedrule of
law that the plea of errorcannot be allowed as an elementvitiating
consentif the party advancing it contributedby its own conductto
the error,or could have avoided it, or if the circumstances were
such as to put that party on notice of a possible error.The Court
considersthat the characterand qualificationsof the persons who saw
the Annex Imap on the Siamese side would alone make it difficultfor
Thai- land to plead error in law.These persons included the
membersof the very Commissionof Delimitationwithinwhose
competencethis sectorof the frontierhad lain.But even apart
fromthis, the Court thinksthat there were
othercircumstancesrelatingto the Annex I map whichmake the plea of
errordifficultto receive. An inspectionindicatesthat the map
itselfdrew such pointedattentionto the Preah Vihear regionthat no
interestedperson,nor anyone chargedwith the duty of scrutinizingit,
could have failed to see what the map was pur- porting to do in
respect of that region.If, as Thailand has argued, the
geographicalconfigurationof the place is such as to make it obvious
to any- one who has been there that the watershedmust lie along the
line of the escarpment(a fact which,if true,must have been no less
evidentin 1908), then the map made it quite plain that the Annex I
line did not follow the escarpmentin this region since it was
plainly drawn appreciably to the northof the whole Preah Vihear
promontory. Nobody looking at the map could be under any
misapprehensionabout that. Next, the map marked Preah Vihear itself
quite clearly as lying on the Cambodian side of the line, using for
the Temple a symbolwhich seems to indicate a rough plan of the
building and its stairways. It would thus seem that, to anyone who
consideredthat the line of the watershedat Preah Vihear ought to
follow the line of the escarpment,or whose duty it was to
scrutinizethe map, therewas everythingin the Annex I map to put him
upon enquiry. Furthermore,as has already been pointed out, the
Siamese Governmentknew or must be presumed to have known,
throughthe Siamese membersof the Mixed Commission,that the Annex I
map had never been formallyadopted by the Commission. The Siamese
authoritiesknew it was the work of French topographicalofficersto
whom they had themselvesentrustedthe work of producingthe maps.They
ac- cepted it withoutany independentinvestigation,and cannot
thereforenow plead any errorvitiatingthe realityof their consent.
The Court concludes thereforethat the plea of errorhas not been
made out. The Court will now considerthe events subsequent to the
period 1904- 1909. The Siamese authoritiesdid not raise any query
about the Annex I map 1044THEAMERICANJOURNALOFINTERNATIONALLAW[Vol.
56 as betweenthemselvesand France or Cambodia, or
expresslyrepudiate it as such, until the 1958 negotiationsin
Bangkok,when,inter altia,the ques- tion of Preah Vihear came under
discussion between Thailand and Cam- bodia.Nor was any question
raised even after 1934-1935, when Thailand carried out a surveyof
her own in this region,and this surveyhad, in Thai- land'sview,
establishedadivergencebetween the map line and the true line of the
watershed-a divergencehaving the effectof placing the Temple
inCambodia.Although, after this date, Thailand eventually produced
some maps of her own showing Preah Vihear as being in Thailand, she
continued,even for public and officialpurposes, to use the Annex
Imap, or othermaps showingPreah Vihear as lying in
Cambodia,withoutraising any query about the matter (her
explanationsas to this will be considered presently).Moreover,the
Court finds it difficultto overlooksuch afact as, for instance,that
in 1937, even after Thailand's own survey in 1934- 1935, and in the
same year as the conclusion of atreaty with France in which, as
will be seen, the established commonfrontierswere reaffirmed, the
Siamese Royal Survey Department produced amap showing Preah Vihear
as lying in Cambodia. Thailand had several opportunitiesof
raisingwith the French authorities the question of the Annex
Imap.There were firstof all the negotiations for the 1925 and 1937
Treaties of Friendship, Commerceand Navigation between France, on
behalf of Indo-China, and Siam.These Treaties, al- thoughthey
provided for a general process of revision or replacementof
previous Agreements,excluded fromthis process the existing
frontiersas they had been establishedunder the Boundary
Settlementsof 1893, 1904 and 1907.Thereby,and in certain more
positive provisions,the Parties confirmedthe
existingfrontiers,whatevertheywere.These were occasions
(particularly in regard to the negotiationsfor the 1937
Treaty,which oc- curred only two years after Thailand's own survey
of the frontierregions had disclosed,in her belief,a serious
divergencebetweenthe map line and the watershedline at Preah
Vihear) on which it would have been natural for Thailand to raise
the matter,if she consideredthe map indicatingthe frontierat Preah
Vihear to be incorrect-occasionson which she could and should have
done so if that was her belief.She did not do so and she even, as
has been seen,produced a map of her own in 1937 showingPreah Vihear
as being in Cambodia.That this map may have been intendedfor
internal militaryuse does not seem to the Court to make it any less
evidence of Thailand's state of mind.The inferencemust
be-particularly in regard to the 1937 occasion-that she accepted or
still accepted the Annex I map, and the line it indicated,even if
she believed it incorrect,even if, afterher own surveyof
1934-1935,she thoughtshe knew it was incorrect. Thailand having
temporarilycome into possession of certain parts of Cambodia,
including Preah Vihear, in 1941, the Ministryof Information of
Thailand published a work entitled "Thailandduring national recon-
struction" in which it was stated in relation to Preah Vihear that
it had now been "retaken" for Thailand.This has been representedby
Thailand as being an erroron the part of a minorofficial.
Nevertheless,similar lan- 1962]JUDICIALDECISIONS1045 guage,
suggestingthat Thailand had been in possession of Preah Vihear only
since about 1940, was used by representativesof Thailand in the
terri- torial negotiations that took placebetween Thailand
andCambodia at Bangkok in 1958. Afterthe war, by a
SettlementAgreementof November1946 withFrance, Thailand accepted a
reversionto the status quo ante 1941.It is Thailand's
contentionthat this reversionto the status quo did not affectPreah
Vihear because Thailand already had sovereigntyover it before the
war.The Court need not discuss this contention,for whetherThailand
did have such sovereigntyis preciselywhat is in issue in these
proceedings. The impor- tant point is that,in consequenceof the war
events,France agreed to set up a
Franco-SiameseConciliationCommissionconsistingof the two
representa- tives of the Parties and threeneutral
Commissioners,whose termsof refer- ence were specificallyto go
into,and make recommendationson an equitable basis in regard to,
any complaintsor proposals for revisionwhich Thailand mightwish to
make as to, inter altia,the frontiersettlementsof 1904 and 1907.The
Commissionmet in 1947 in Washington,and here thereforewas
anoutstandingopportunityfor Thailand to claim arectificationof the
frontierat Preah Vihear on the ground that the delimitationembodied
a serious errorwhichwould have caused Thailand to reject it had she
known of the error in 1908-1909.Infact, although Thailand made
complaints about the frontierline in a considerablenumberof
regions,she made none about Preah Vihear.She even (12 May 1947)
filedwith the Commissiona map showingPreah Vihear as lying in
Cambodia.Thailand contendsthat this involved no adverse
implicationsas regards her claim to the Temple, because the Temple
area was not in issue beforethe Commission,that it was
otherregionsthat were under discussion,and that it was in
relationto these that the map was used.But it is precisely the fact
that Thailand had raised these other questions,but not that of
Preah Vihear, which requires explanation; for, everythingelse
apart, Thailand was by this time well aware, fromcertainlocal
happeningsin relationto the Temple, to be men- tionedpresently,that
France regardedPreah Vihear as being in Cambodian territory-evenif
this had not already and long since been obviousfromthe
frontierline itself,as mapped by the French authoritiesand
communicated to the Siamese Governmentin 1908.The natural
inferencefromThailand's failure to mentionPreah Vihear on this
occasion is, again, that she did not do so because she accepted the
frontierat this point as it was drawn on the map, irrespectiveof
its correspondencewiththe watershedline. As regardsthe use of a map
showingPreah Vihear as lying in Cambodia, Thailand maintains that
this was for purely cartographicalreasons, that therewere no
othermaps, or none that were so convenient,or none of the
rightscale for the occasion.The Court does not findthis explanation
con- vincing.Thailand could have used the map but could also have
entered some kind of reservationwith France as to its correctness.
This she did not do. As regardsher failure even to raise the
questionof the map as such until 1958, Thailand states that this
was because she was, at all material times,
1046THEAMERICANJOURNALOFINTERNATIONALLAW[Vol. 56 in possessionof
Preah Vihear; thereforeshe had no need to raise the mat- ter.She
indeed instancesher acts on the ground as evidencethat she never
accepted the Annex I line at Preah Vihear at all, and contendsthat
if she never accepted it she clearly had no need to repudiate it,
and that no ad- verse conclusionscan be drawn fromher failureto do
so.The acceptability of this explanationmust obviouslydepend on
whetherin fact it is the case that Thailand's conduct on the ground
affordsex post facto evidence suffi- cient to show that she never
accepted the Annex Iline in 1908 in respect of Preah Vihear, and
consideredherselfat all material times to have the sovereigntyover
the Temple area. The Court has consideredthe evidence furnishedby
Thailand of acts of anadministrativecharacter performedby her
officialsat or relative to Preah Vihear.France, and
subsequentlyCambodia, in view of her title founded on the Treaty of
1904, performedonly a very few routineacts of administrationin this
small, desertedarea.It was specificallyadmittedby Thailand in the
course of the oral hearingthat if Cambodia acquired sover-
eigntyoverthe Temple area by virtueof the frontiersettlementof
1904, she did not subsequentlyabandon it, nor did Thailand
subsequentlyobtain it by any process of acquisitive prescription.
Thailand's acts on the ground were thereforeput forwardas evidence
of conduct as sovereign,sufficient to negativeany
suggestionthat,under the 1904 Treaty settlement,Thailand accepted a
delimitationhaving the effectof attributingthe sovereigntyover
Preah Vihear to Cambodia.It is thereforefromthis standpointthat the
Court must considerand evaluate these acts.The real question is
whether theysufficedto effaceor cancel out the clear impressionof
acceptance of the frontierline at Preah Vihear to be derived
fromthe various considerations already discussed. With one or two
importantexceptionsto be mentionedpresently,the acts concernedwere
exclusivelythe acts of local, provincial,authorities. To the
extentthat theseactivitiestook place, it is not clear that theyhad
reference to the summitof Mount Preah Vihear and the Temple area
itself,rather than to places somewherein the vicinity. But
howeverthat may be, the Court findsit difficultto regard such local
acts as overridingand negativing the consistentand
undeviatingattitude of the central Siamese authorities to the
frontierline as mapped. Inthis connection,much the most
significantepisode consisted of the visit paid to the Temple in
1930 by Prince Damrong, formerlyMinisterof the Interior, and at
this time President of the Royal Institute of Siam, charged with
duties in connectionwith the National Library andwith
archaeological monuments. The visit was part of an archaeological
tour made by the Prince with the permissionof the King of Siam, and
it clearly had a quasi-officialcharacter. When the Prince arrived
at Preah Vihear, he was officiallyreceived there by the French
Resident for the adjoining Cambodian province,on behalf of the
Resident Superior, with the French flag flying. The Prince could
not possibly have failed to see the implica- tions of a receptionof
this character. A clearer affirmationof title on the French
Indo-Chineseside can scarcely be imagined.It demanded a reac-
1962]JUDICIALDECISIONS1047 tion.Thailand did nothing.
Furthermore,when Prince Damrong on his return to Bangkok sent the
French Resident some photographsof the oc- casion, he used language
which seems to admit that France, throughher Resident,had acted as
the host country. The explanations regarding Prince Damrong's visit
given on behalf of Thailand have not been found convincingby the
Court.Looking at the incidentas a whole,it appears to have
amountedto a tacit recognitionby Siam of the sovereigntyof Cambodia
(under French Protectorate) over Preah Vihear, througha failure to
react in any way, on an occasion that called for a reaction in
order to affirmor preserve title in the face of an obvious rival
claim.What seems clear is that either Siam did not in fact believe
she had any title-andthis would be whollyconsistentwith her at-
titude all along, and thereafter,to the Annex Imap and line-orelse
she decided not to assert it, which again means that she accepted
the French claim,or accepted the frontierat Preah Vihear as it was
drawn on the map. The remainingrelevant facts must now be
stated.InFebruary 1949, not long after the conclusion of the
proceedings of the Franco-Siamese ConciliationCommission,in the
course of which,as has been seen, Thailand did not raise the
question of Preah Vihear, France addressed a Note to the
Governmentof Thailand stating that areport had been received of the
stationingof four Siamese keepers at the Temple, and asking for
informa- tion.There was no reply to this note, nor to a
follow-upNote of March 1949.In May 1949, France sent a furtherNote,
setting out briefly,but quite explicitly,the groundson whichshe
consideredPreah Vihear to be in Cambodia, and pointingout that a
map produced by Thailand herselfhad recognizedthis fact.The
withdrawal of the keepers was requested.Al- thoughthere was an
error in this Note, the significanceof the latter was that it
contained an unequivocal assertion of sovereignty. This French Note
also receivedno reply.In July 1950, a furtherNote was sent.This too
remainedunanswered. In these circumstancesCambodia,on attainingher
independencein 1953, proposed, for her part, to send keepers or
guards to the Temple, in the assertion or maintenance of her
position.However, finding that Thai keeperswere already there,the
Cambodiankeeperswithdrew,and Cambodia sent a Note dated January
1954 to the Governmentof Thailand asking for information. This
received a mere acknowledgment,but no explanation. Nor was
there,even then,any formalaffirmationof Thailand's claim.At the end
of March 1954, the Governmentof Cambodia, drawing attentionto the
fact that no substantivereply to its previous Note had been
received, notifiedthe Governmentof Thailand that it now proposed to
replace the previouslywithdrawnCambodian keepers or guards by some
Cambodian troops.In this Note Cambodia specificallyreferredto the
justificationof the Cambodian claim contained in the French Note of
May 1949.This Cambodian Note also was not answered.However, the
Cambodian troops were not in fact sent; and in June 1954, Cambodia
addressed to Thailand a furtherNote statingthat,as informationhad
been receivedto the effectthat Thai troops were already in
occupation, the despatch of the Cambodian
1048THEAMERICANJOURNALOFINTERNATIONALLAW[Vol. 56 troops had been
suspended in order not to aggravate the situation.The Note went on
to ask that Thailand should either withdrawher troops or
furnishCambodia withher views on the matter. This Note equally
received no reply.But the Thai "troops"(the Court understandsthat
they are in fact a police force) remained. Again, therefore,it
would seem that Thai- land, while taking certain localaction,
wasnot prepared to deny the French and Cambodian claim at the
diplomaticlevel. No furtherdiplomatic correspondencewas produced to
the Court; but eventually,in 1958, aconferencewas held at Bangkok
between Thailand and Cambodia,to discuss various
territorialmattersin dispute betweenthe Parties, including that of
Preah Vihear.The representativeof Thailand having declined to
discuss the legal aspects of the matter,the negotiations broke down
and Cambodia institutedthe presentproceedings. The Courtwill now
state the conclusionsit draws fromthe facts as above set out. Even
if therewere any doubt as to Siam's acceptance of the map in 1908,
and henceof the frontierindicatedthereon,the Court would
consider,in the light of the subsequentcourse of events,that
Thailand is now precluded by her conduct fromassertingthat she did
not accept it.She has, for fifty years, enjoyed such benefitsas the
Treaty of 1904 conferredon her, if only the benefitof a stable
frontier. France, and throughher Cambodia, relied on Thailand's
acceptance of the map.Since neitherside can plead error, it is
immaterialwhetheror not this reliance was based on a belief that
the map was correct. It is not now open to Thailand, while
continuingto claim andenjoy the benefitsof the settlement,to deny
that she wasever a consentingparty to it. The Court
howeverconsidersthat Thailand in 1908-1909 did accept the Annex I
map as representingthe outcomeof the work of delimitation,and hence
recognizedthe line on that map as being the frontierline, the
effect of which is to situate Preah Vihear in Cambodian territory.
The Court considersfurtherthat,looked at as a whole,Thailand's
subsequentconduct confirmsand bears out her original acceptance,
and that Thailand's acts on the ground do not sufficeto negative
this.Both Parties, by their con- duct, recognizedthe line and
therebyin effectagreed to regard it as being the frontierline. The
Court must now consider two furthermatters. Thailand contends that
since 1908, and at any rate up to her own 1934-1935 survey,she be-
lieved that the map line and watershedline coincided,and
thereforethat if she accepted the map line, she did so only in that
belief.It is evident that such a contentionwould be quite
inconsistentwith Thailand's equally stronglyadvanced contentionthat
these acts in the concreteexerciseof sov- ereigntyevidenced her
belief that she had sovereigntyover the Temple area: for if
Thailand was trulyunder a misapprehensionabout the Annex I
line-ifshe really believedit indicatedthe
correctwatershedline-thenshe must have believed that, on the basis
of the map and her acceptance of it, the Temple area lay
rightfullyin Cambodia.If she had such a belief-and such a belief is
implicit in any plea that she had accepted the Annex I
1962]JUDICIALDECISIONS1049 map only because she thoughtit was
correct-then her acts on the ground would have to be regarded as
deliberateviolationsof the sovereigntywhich (on the basis of the
assumptionsabove stated) she must be presumed to have
thoughtCambodia to possess.The conclusionis that Thailand cannot
allege that she was under any misapprehensionin accepting the Annex
I line, for this is whollyinconsistentwith the reason she gives for
her acts on the ground,namely that she believed herselfto possess
sovereigntyin this area. It may be added that even if Thailand's
plea of misapprehensioncould, in principle,be accepted, it should
have been advanced shortlyafter Thai- land'sown survey of the
disputed region was carried out in 1934-1935. Since then Thailand
could not have been under any misapprehension. There is finallyone
furtheraspect of the case with which the Court feels it necessaryto
deal.The Court considersthat the acceptance of the Annex I map by
the Parties caused the map to enterthe treatysettlementand to
becomean integralpart of it.It cannot be said that this process
involved a departurefrom,and even a violation of, the termsof the
Treaty of 1904, whereverthe map line divergedfromthe line of the
watershed,for, as the Court sees the matter,the map (whetherin all
respectsaccurate by refer- ence to the true watershedline or not)
was accepted by the Parties in 1908 and thereafteras
constitutingthe result of the interpretationgiven by the two
Governmentsto the delimitationwhich the Treaty itselfrequired.In
otherwords,the Parties at that time adopted an interpretationof the
treaty settlementwhich caused the map line, in so far as it may
have departed fromthe line of the watershed,to prevail over the
relevant clause of the treaty.Even if, however,the Court were
called upon to deal with the matternow as one solely of
ordinarytreatyinterpretation,it considersthat the interpretationto
be given would be the same,for the followingreasons. In
general,when two countriesestablisha frontierbetweenthem,one of the
primaryobjects is to achieve stabilityand finality. This is
impossible if the line so establishedcan, at any moment,and on the
basis of acon- tinuously available process, becalledinquestion,
andits rectification claimed, wheneverany inaccuracy by referenceto
aclause in the parent treatyis discovered. Such a processcould
continueindefinitely,and finality would never be reached so long as
possible errorsstill remainedto be dis- covered.Such a frontier,so
far from being stable, would be completely precarious.It must be
asked why the Parties in this case provided for a
delimitation,instead of relying on the Treaty clause indicating
that the frontierline in this region would be the watershed. There
are boundary treatieswhich do no more than referto a watershed
line, or to a crestline, and whichmake no provision for any
delimitationin addition.The Parties in the present case must have
had a reason for taking this furtherstep. This could only have been
because they regarded a watershedindicationas insufficientby itself
to achieve certaintyand finality. Itis precisely to achieve this
that delimitationsand map lines are resortedto. Various
factorssupport the view that the primaryobject of the Parties in
the frontiersettlementsof 1904-1908 was to achieve certaintyand fi-
1050THEAMERICANJOURNALOFINTERNATIONALLAW[Vol. 56 nality.From the
evidence furnishedto the Court, and from the state- mentsof the
Parties themselves,it is clear that the whole questionof Siam's
very long frontierswith French Indo-China had, in the period prior
to 1904, been a cause of uncertainty,trouble and
friction,engenderingwhat was describedin one
contemporarydocumentplaced beforethe Court as a state of "growing
tension" in the relations between SiamandFrance. The Court thinksit
legitimateto conclude that an important,not to say a paramount
object of the settlementsof the 1904-1908 period(which broughtabout
a comprehensiveregulationof all outstandingfrontierques- tions
betweenthe two countries),was to put an end to this state of
tension and to achieve frontierstabilityon a basis of certaintyand
finality. In the Franco-Siamese Boundary Treaty of 23 March 1907,
the Parties recitedin the preamblethat theywere desirous"of
ensuringthe finalregu- lation of all questionsrelatingto the
commonfrontiersof Indo-China and Siam".A furthertokenof the same
object is to be found in the desire,of which the
documentationcontains ample evidence,and which was evinced by both
Parties, for natural and visible frontiers. Even if, as the Court
stated earlier, this is not in itself a reason for holding that the
frontier must follow a natural and visible line, it does support
the view that the Parties wanted certaintyand finalityby means of
natural and visible lines. The same view is stronglysupportedby the
Parties' attitude over fron- tiers in the 1925 and 1937 Treaties.By
specificallyexcluding frontiers fromthe process of revisionof
previous treaties,which the 1925 and 1937 Treaties
otherwiseeffected,the Parties bore witness to the paramount im-
portancethey attached to finalityin this field. Their attitude in
1925 and 1937 can properlybe taken as evidencethat they equally
desired finalityin the 1904-1908period. The indication of the line
of the watershed in Article 1of the 1904 Treatywas itselfno
morethan an obviousand convenientway of describing a frontierline
objectively,thoughin general terms. There is, however,no reason to
thinkthat the Parties attached any special importanceto the line of
the watershedas such, as compared with the overridingimportance,in
the interestsof finality,of adheringto the map line as
eventuallydelimited and as accepted by them. The
Court,therefore,feels bound,as a matterof treatyinterpretation,to
pronouncein favour of the line as mapped in the disputed area.
Given the grounds on which the Court bases its decision,it
becomesun- necessaryto considerwhether,at Preah Vihear, the line as
mapped does in fact correspondto the true watershedline in this
vicinity,or did so cor- respond in 1904-1908,or, if not, how the
watershedline in fact runs. Referringfinallyto the Submissions
presented at the end of the oral proceedings,the Court, for the
reasons indicated at the beginningof the presentJudgment,findsthat
Cambodia's firstand second Submissions,call- ing for
pronouncementson the legal status of the Annex I map and on the
frontierline in the disputed region,can be entertainedonly to the
extent that they give expressionto grounds,and not as claims to be
dealt with in the operativeprovisions of the Judgment. It findson
the other hand that 1962]JUDICIAL DECISIONS1051 Thailand, after
having stated her own claim concerningsovereigntyover Preah Vihear,
confinedherselfin her Submissionsat the end of the oral
proceedingsto argumentsand denials opposingthe contentionsof the
other Party, leaving it to the Court to word as it sees fitthe
reasons on which its Judgmentis based. In the presence of the
claims submittedto the Court by Cambodia and Thailand,
respectively,concerningthe sovereigntyover Preah Vihear thus in
dispute betweenthese two States, the Court findsin favour of
Cambodia in accordance with her third Submission. It also findsin
favour of Cam- bodia as regards the fourthSubmission concerningthe
withdrawalof the detachmentsof armed forces. As regards the
fifthSubmissionof Cambodia concerningrestitution,the Court
considersthat the request made in it does not representany exten-
sion of Cambodia's original claim (in which case it would have been
irre- ceivable at the stage at which it was firstadvanced).Rather
is it, like the fourth Submission,implicit in, andconsequential on,
the claim of sov- ereigntyitself.On the other hand, no
concreteevidence has been placed beforethe Court showingin any
positiveway that objects of the kind men- tioned in this
Submissionhave in fact been removedby Thailand fromthe Temple or
Temple area since Thailand's occupationof it in 1954.It is true
that Thailand has not so much denied the allegation as
contendedthat it is irreceivable. In the circumstances,however,the
question of restitutionis one on which the Court can only give a
findingof principle in favour of Cambodia,withoutrelatingit to any
particular objects. For these reasons, THECOURT, by nine votes to
three, findsthat the Temple of Preah Vihear is situated in
territoryunder the sovereigntyof Cambodia; finds in consequence, by
nine votes to three, that Thailand is under an obligation to
withdraw any military or police forces,or otherguards or
keepers,stationedby her at the Temple, or in its vicinity on
Cambodian territory; by seven votes to five,3 that Thailand is
under an obligation to restoreto Cambodia any objects of the kind
specifiedin Cambodia's fifthSubmission4which may, since the date of
the occupation of the Temple by Thailand in 1954, have been removed
fromthe Temple or the Temple area by the Thai authorities. 3 On
this point Judges Tanaka and Morelli joined the dissentingJudges
(Moreno Quintana,WellingtonKoo, and Sir Percy Spender), on the
groundthat the Court shouldnot pass upon the Fifth Submissionby
Cambodia,since it was not put forward untilduringthe courseof the
hearings. 4 The Fifth Submission,put forwardby Cambodia on March
20, 1962, asked the Court " to adjudge and declare that the
sculptures,stelae, fragmentsof monuments, sandstonemodeland
ancientpottery whichhave been removedfromthe Templeby the Thai
authoritiessince 1954 are to be returnedto the Governmentof the
Xingdomof Cambodiaby the Governmentof Thailand."
1052THEAMERICANJOURNALOFINTERNATIONALLAW[Vol. 56 [Concurring in the
result, Judges Alfaro and Fitzmaurice gave indi- vidual opinions.
Judge Alfaro discussed at lengththe principle of "estop- pel"or
"preclusion" "that a State party to an internationallitigationis
bound by its previous acts or attitudewhen they are in
contradictionwith its claims in the litigation."Pointing out the
differenceof this principle fromthe Anglo-Americanlaw of
estoppel,he declared that "Itspurpose is always the same: aState
must not be permittedto benefitby its own in- consistencyto the
prejudice of another State,"and said:"Failureof a State to assert
its right when that right is openly challenged by another State can
only mean abandonmentto [of] that right."Judge Fitzmaurice wished
to discuss certainpoints of the case more fully. Inhis
dissentingopinion Judge Moreno Quintana held the treaty text more
importantthan maps, that the interpretationof the treaty called for
a watershedboundary,and that the watershedfollowedthe edge of the
cliff of the promontoryon whichthe Temple is situated,thus placing
the Temple in Thailand.Judge Wellington Koo'sdissentingopinion
concluded that the "Annex map"did not have the characterof an
internationalagree- ment; that Thailand's conduct did not show
acquiescence in any line plac- ing the Temple in Cambodia; that
there was no ground to hold Thailand accountablefor acquiescenceor
for the application of the idea of preclusion or estoppel; urged
that independentexperts should have found the actual watershed,and
concludedthat he could not reach a satisfactoryconclusion as to the
exact boundary withoutknowingthe answers to technical ques- tions
concerningthe watershed lineinthe disputed area.SirPercy Spender
gave a lengthydissentingopinion in whichhe found no agreement to
deviate fromthe treatyline of the watershed,and that the Annex I
map did not in the vicinity of the Temple indicate the real
agreementof the parties, although neither Francenor Thailand
wasawareof this dis- crepancy until long after the map was
published.Hedid not find any basis for holdingthat acquiescence had
precluded Thailand fromasserting the true treaty-boundaryline.He
stated: There is however,in my view, no foundationin
internationallaw for the propositionthat an act of recognitionby a
State of or acquiescence by aState in a situation of fact or law is
aunilateral juridical act which, operating of its own force, has
the legal consequence of pre- cluding a party giving or making it
from thereafterchallengingthe situation which is the subject of
recognitionor acquiescence. The principleof preclusionis a
beneficientand powerfulinstrument of
substantiveinternationallaw.Based as it is upon the necessityfor
good faith betweenStates in their relationsone with another,it is
not to be hedged in by artificialrules.It should not howeverbe
permitted to becomeso indefiniteas to acquire the
somewhatformlesscontentof a maxim. And since the principle,when it
is applicable to any given set of facts, substitutesrelative truth
for the judicial search for the truth,it should be applied with
caution. In my opinion the principle operates to preventaState
contesting beforethe Court a situationcontraryto a clear and
unequivocal repre- sentationpreviouslymade by it to another State,
either expresslyor impliedly,on which representationthe otherState
was, in the circum- stances,entitledto rely and in fact did
rely,and as a result that other State has been prejudiced or the
State making it has secured some benefitor advantage for itself.
Unless the elementsso stated can, in any particular case, be shown
to exist,the principle has no application.
1962]JUDICIALDECISIONS1053 I greatlydoubt whetherany of the
elementsof preclusionhave been established by Cambodia.Even were it
established that Thailand's conduct did amount to some clear
andunequivocal representation, and that France relied upon it and
was entitled to do so, Ido not think there is any evidence that
France-orCambodia-suffered any prejudice.] Resolution1731 (XVI)of
General Assemblyrequestingadvisoryopin- ion-objections to giving
opinion based on proceedingsin General Assembly-interpretationof
meaning of "expenses of the Organi- zation"-Article17, paragraphs 1
and 2 of Charter-lack of justifi- cation for
limitingterms"budget"and "expenses "-Article17 in context of
Charter-respective functions of Security Council and
GeneralAssembly-Article 11, paragraph 2, in relationto budgetary
powers of General Assembly-role of General Assemblyin mainte- nance
of internationalpeace and security-agreementsunder Ar- ticle
43-expensesincurredfor purposes of United Nations-obliga- tions
incurred bySecretary-Generalacting under authority of Security
Council orGeneral Assembly-nature of operations of UNEFand
ONUC-financing of UNEFand ONUC based on Article 17, paragraph
2-implententationby Secretary-Generalof Security Council
resolutions-expendituresfor UNEFand ONUC and Article 17, paragraph
2, of Charter 1 CERTAINEXPENSESOF THE UNITEDNATIONS(ARTICLE17,
PARAGRAPH 2, OF THE CHARTER).2I.C.J. Reports,1962, p. 151.
InternationalCourt of Justice,3AdvisoryOpinion of July 20, 1962.
[Resolution 1731(XVI),adopted December 20, 1961, by the General
Assembly,read: The General Assembly, Recognizing its need for
authoritativelegal guidance as to obliga- tions of MemberStates
under the Charterof the United Nations in the matterof financingthe
United Nations operationsin the Congo and in the Middle East,
1.Decides to submit the following question to the International
Court of Justicefor an advisoryopinion: "Dothe
expendituresauthorizedin General Assemblyresolutions 1583 (XV)and
1590 (XV)of 20 December 1960, 1595(XV)of 3 April 1961, 1619(XV)of
21 April 1961 and1633(XVI)of 30 October1961 relatingto the United
Nations operationsin the Congo undertakenin pursuance of the
Security Council resolutionsof 14 July, 22 July and 9 August 1960,
and 21 February and 24 Novem- ber 1961, andGeneral Assembly
resolutions 1474 (ES-IV)of 20 September1960 and 1599
(XV),1600(XV),and 1601(XV) of 15 1 Captionby the Court. 2Full text
of majorityopinion,except for introductorymatter,and digests of re-
mainder,by Wm. W. Bishop, Jr. 8 Composedfor this case of
PresidentWiniarski,Vice PresidentAlfaro,and Judges
Basdevant,Badawi, MorenoQuintana,WellingtonKoo, Spiropoulos,Sir
Percy Spender, Sir GeraldFitzmaurice,Koretsky,Tanaka, Bustamantey
Rivero,Jessup,and Morelli.