53

SEPARATE OPINION BY JONKHEER VAN EYSINGA.
[Tvanslation. |

The Judgment does not entirely express my opinion ; in these
circumstances, I would subjoin to it a statement of my separ-
ate opinion on certain parts of the case.

*
% *

In each of the two actions which have been brought before
the Court in the present case—in the main Netherlands action
and in the Belgian counter-claim—the applicant Party alleges
that certain hydraulic works are inconsistent with the Treaty
of May 12th, 1863, concerning the régime for the diversion of
water from the Meuse. Neither the Netherlands in the prin-
cipal action, nor Belgium in the counter-claim, alleges that the
hydraulic works in question are contrary to general interna-
tional law. Such an assertion had been made inter alia by
Belgium in regard to the feeding of the Juliana Canal with
Meuse water, as appears from the Belgian note transmitted to the
Netherlands Government on April 28th, 1921 (Belgian Counter-
Memorial, p. 27). That note declared that this “régime would
be in conflict with the general principles of international law
governing the utilization of international rivers by the riparian
States’. But, in the present case, general international law, to
which Belgium has alluded on several occasions, must be left
on one side; we are here only concerned with the Treaty of
1863.

What the two States are asking the Court to give them is
an interpretation of that Treaty with special reference to cer-
tain hydraulic works, the compatibility of which with the
Treaty is a subject of dispute. It is therefore one of those
cases which, according to Article 13 of the Covenant of the
League of Nations, is primarily suitable for judicial settlement.
Each of the Parties is entitled to ask the Court for an inter-
pretation of the Treaty, and the Court is not entitled to refuse
to give this interpretation.

*
% *

It will be seen from the foregoing observations that the
first thing to do is to ascertain the character, the scope and
the interpretation of the Treaty of 1863.

The Treaty of 1863 put an end, by means of a compromise,
to a dispute which had existed between the two countries for
several years.

53
A./B. 70 (WATER FROM THE MEUSE).—OP, VAN EYSINGA 54

The Netherlands alleged that Belgium was wrongfully divert-
ing (aftappen) Meuse water in order to feed her new system
of canals in the Campine and her irrigation works in the Cam-
pine; this water, which was withdrawn from the Meuse, was
to a considerable extent conveyed to the Scheldt. Liége, an
ancient port on the Meuse, and the Belgian basin of the Meuse
in general, had used the Meuse from the earliest times as a
natural navigable waterway, terminating in. Holland. However,
after the dissolution of the Kingdom of 1815, which comprised
Belgium, Luxemburg and the present territory of the Nether-
lands, Belgium endeavoured to direct the traffic of her Meuse
basin towards Antwerp; she did this in particular with the
help of her canals in the Campine which were designed to link
the Zuid-Willemsvaart, and thereby the Meuse, to the great
Belgian maritime port—as indeed is indicated by the name:
Meuse-Scheldt Junction Canal. My reason for mentioning this
fact is to show that the Netherlands Government did not, in
the dispute which was regulated by the Treaty of 1863, any
more than in the suit now under consideration, oppose the
diversion of the traffic of the Belgian Meuse basin towards
Antwerp. Neither in the dispute in the XIXth century, nor in
that in the XXth century has there been any question of an
objection to the diversion of traffic; in both cases the disputes
were solely concerned with objections to the withdrawal (aftap-
ping) of Meuse water effected by Belgium.

It is not superfluous to point out that when the Nether-
lands, in the dispute in the middle of the XIXth century,
alleged that Belgium was arbitrarily withdrawing water from
the Meuse, the objection in no way concerned the quantity of
water necessary for navigation in the Zuid-Willemsvaart, or,
later on, in the prolongation of that canal as far as Liége.
There may be different opinions as to whether the Zuid-Willems-
vaart is, or is not, a lateral canal of the Meuse—the Belgian
Counsel, M. Delmer, says that it is (Oral Pleadings, p. 86);
the Belgian Counsel, Me. Marcq, says that it is not (Oral
Pleadings, p. 189); but one thing is certain, namely that when
King William I, as early as 1819, ordered an investigation of
the problem, the initial step which led to the construction of:
the Zuid-Willemsvaart, the object in view was to provide the
important industrial and mining districts of the present Belgian
Meuse basin with a better navigable waterway. The results of
the investigations carried out by the Waterstaat showed that a
canal could be made which would be much shorter than the
Meuse and would offer a navigable waterway, practically always
available, unlike the Meuse which suffered at times from an
insufficiency and at times from a superabundance of water,
either of which conditions were an obstacle to navigation during
considerable parts of the year. The Zuid-Willemsvaart was

54
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 55

ready for use in 1826, and its prolongation as far as Liége
was ready in 1850, or at the beginning of 1851. It was known
beforehand that these canals would use a certain quantity of
Meuse water, but that inevitable consequence of an improve-
ment in the communications by water was all the more easy
of acceptance because the quantity required was inconsiderable.
It should be noted, in this connection, that Article V, para-
graph x, of the Treaty of 1863 allots a volume of two cubic
metres, or even as little as 1.50 cubic metre, per second to the
Zuid-Willemsvaart below Loozen and to the canals branching off
from this part of the Zuid-Willemsvaart, and to the Netherlands
irrigation channels. And, in the case of the Liége-Maestricht
Canal, neither the Convention of 1845, which provided for its
construction, nor the Treaty of 1863 said anything on the
subject of its lock-water, which was very natural because the
volume of such water is extremely small, viz., one-tenth of a
cubic metre per second, a quantity less than the margin of
error which occurs in measuring the discharge through the
feeder at Maestricht, as is pointed out on page 15 of the
Belgian Rejoinder.

In point of fact, the Netherlands never made any complaint
in regard to the small quantities of water requisite to enable
the Zuid-Willemsvaart and the canal prolonging it to Liége
to be utilized as a waterway.

But the situation was very different when Belgium began to
use the two navigable canals to convey the large quantities of
water which she found that she required for her system of
canals in the Campine, then in course of construction, and for
her projected irrigation works in the Campine. Belgium began
to take the supplementary water required for her canals and
irrigation works in the Campine at three different intakes. All
of them were situated in Belgian territory.

First, there was the intake at Hocht, quite close to the spot
where the Zuid-Willemsvaart leaves Netherlands territory. A
feeder drawing its water from the Meuse, which at that point
runs close alongside the canal, was constructed in 1837 on the
right bank of the canal.

Secondly, as soon as the Liége-Maestricht Canal was com-
pleted, Belgium began to use it also as a feeder for the system
of canals and irrigation channels in the Campine. For this
purpose, large quantities of Meuse water were diverted at Liége
into the lateral canal at Maestricht; this process was facili-
tated, subsequently, by the construction of a barrage which
raised the level of the Meuse at the place where the
lateral canal branched off. In order not to hamper navigation
unduly in the lateral canal, the large quantities of water were
introduced into the canal during the night, with the result that

55
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 56

on the following day, at a particular time, the level of. the
Meuse in Netherlands Limburg fell considerably, so that it was
described there as being subject to a flux and reflux, like that
of the sea, only more regular.

In order that the Zuid-Willemsvaart should afford a rapid
passage to the large quantities of Meuse water diverted at
Liége, it was necessary to increase the velocity of its current.
This was done at the very time when the Liége-Maestricht
Canal was taken into use, namely, about the beginning of 1851.
For this purpose, a third intake, or rather a cascade, was con-
structed in Belgian territory to the left of the old lock 19, near
Hocht, where “‘the lateral derivation’ was deepened and enlarged.

The statement of reasons which was drawn up by M. Rogier,
the Belgian Prime Minister, and is dated on the day after the
signature of the Treaty (Netherlands Memorial, p. 21), makes
repeated mention of the intakes at Liége and at Hocht; and
in his statement on May 1oth, the Belgian Counsel, M. Delmer,
clearly described the situation of which the Netherlands Govern-
ment had complained prior to 1863.

In fact, Belgium, in order to feed her new system of Campine
canals and her Campine irrigation works, took water wherever
she could find it, and the three intakes on the Meuse were
supplemented by water drawn off from several of the streams and
water-courses which flowed towards Netherlands North Brabant ;
at the same time, the water which had been used for irrigation
was discharged, in part, into Netherlands territory, where it
caused inundations, which were very mischievous, especially in
the hay-making season.

The withdrawal of water for the needs of the Campine
caused the Netherlands to make repeated representations to
the Cabinet at Brussels. Two international commissions studied
the problem in 1856 and in 1858, but without success. In
1860, the Second Chamber of the States-General appointed
a commission of enquiry, and in the following year a conven-
tion was signed at Brussels which maintained the situation as
it was in the neighbourhood of Hocht; this convention was
rejected by the Second Chamber of the States-General. Further
negotiations followed, in conjunction with the discussions
concerning the redemption of the Scheldt tolls and commercial
arrangements; until finally the Treaty of May r2th, 1863, recon-
ciled the divergent standpoints and put an end to the dispute.

*
* *

What are the provisions of the Treaty of 1863?
The essential feature of the Treaty was that a considerable
portion of the discharge of the international river was assigned

. 56
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 57

to Belgium, even at periods of the year when the Meuse is
very low. The Treaty, therefore, derogated from the normal
state of affairs, according to which the discharge of an inter-
national river belongs to that river. The quantity of water to
be withdrawn for Belgium, as laid down in Articles IV and V
of the Treaty, is fixed, and is therefore both a maximum and
a minimum quantity. The Netherlands have also to receive
a certain quantity of water, which, however, is far less than
that allotted to Belgium ; on the other hand, it is liable to be
increased, within certain limits and subject to certain condi-
tions (Art. V, para. 2, and Art. XI).

The considerable withdrawals of Meuse water for the canals
and irrigation works of the Campine were rendered feasible
by means of a variety of measures designed to neutralize the
undesirable consequences of these diversions of water. The
water was henceforward to be withdrawn solely at Maestricht
(Art. I); the Zuid-Willemsvaart was to undergo certain alter-
ations (Arts. IJ and III); measures were to be taken to
prevent inundations in the Netherlands as a result of irrigation
in Belgium (Art. VI); certain works were to be carried out
on the Meuse between Maestricht and Venlo (Art. IX). It
should be added that Article VII prohibits the withdrawal of
water, in the future, from certain water-courses flowing towards
the Netherlands.

It was the withdrawal of large quantities of water from the
Meuse, on the one hand, and the measures to offset the
undesirable consequences of that withdrawal, on the other hand,
that constituted the compromise established by the Treaty,
which, as its Preamble states, regulated, permanently and
definitively, the régime of diversions of water from the Meuse.
The withdrawal of water from the Meuse comes first, and the
other provisions of the Treaty, though also important, are
the effect of that withdrawal.

For the supply of water to all the canals situated below
Maestricht, and to the irrigation channels in the Campine and
the Netherlands, Article I of the Treaty of 1863 substitutes
a single intake, which is to be established in Netherlands
territory in place of the existing intakes, which were all in
Belgian territory.

Belgium has maintained that the monopoly accorded to the
intake at Maestricht only applied in the sector of that river
below Maestricht, as far down as Venlo. This contention, which
implies that, above Maestricht, it would be lawful to divert
water from the Meuse in order to feed canals situated below
Maestricht, does not appear to me to be justified.

It should be pointed out, in this connection, that Article I,
which speaks of the establishment of the feeder for all the canals
situated below Maestricht and for the irrigation works in the

57
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 58

Campine and the Netherlands, is drawn up in entirely general
terms, so far as concerns the places at which the obligation to
refrain from installing a new intake on the Meuse applies. This
obligation applies at every place where it would be possible to
construct an intake for feeding any canal whatsoever situated
below Maestricht, or for feeding irrigation works in the Campine
and the Netherlands. As is known, the principal intake existing
prior to 1863 was situated above Maestricht. This was the
important intake which Belgium operated at Liége, and which
is repeatedly mentioned in the statement of reasons by the
Prime Minister, M. Rogier.

The Belgian argument endeavours to interpret Article I of
the Treaty by means of Article IX. In this way it brings the
Maestricht-Venlo sector, which is mentioned in the latter Article,
within the compass of Article I. But in so doing, it restricts,
unjustifiably, the very general scope of Article I, and it forgets
that the only link between the two Articles is that between
cause (Art. I) and effect (Art. IX). I am well aware that the
Belgian argument avers that the principal aim of the Treaty
was the improvement of the Meuse, which would appear to
justify the interpretation of Article I from the standpoint of
Article IX. But it is clear from the Preamble of the Treaty,
inter alia, that the aim of the Treaty is to regulate ‘‘the system
of diversions of water from the Meuse’; and the essential
feature of the Treaty, as has already been pointed out, consists
of the ten cubic metres per second that are to be taken from
the Meuse, out of which amount eight cubic metres per second
are assigned to Belgium t. The deterioration of the Meuse which
results from this diversion of Meuse water constitutes, as is said
in M. Rogier’s statement of reasons, a disturbance of the equili-
brium which must, in fairness, be re-established by the carrying
out of certain works on the Meuse. Article IX is indeed an
effect of Article I, and seeks to neutralize its consequences.
Article IX should properly be interpreted in the light of
Article I, whereas an interpretation in the inverse order runs
directly counter to the very general import of Article I.

To the foregoing I would add a practical observation.

It has been suggested that Article I of the Treaty of 1863
only prohibits the establishment of intakes on the Meuse below
Maestricht, as far down as Venlo. But is it realized that, if
that were so, the practical men, the engineers, who according
to the Belgian statements were responsible for framing the
treaty, would have strayed very far from the sphere of real-
ities? I will explain.

1 Except in regard to the barrage of Borgharen, the present Opinion dis-
regards, in general, the case in which the river is at or below the low level.

58
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 59

It has been pointed out that even the Hocht intake—which
was however situated very close to the spot where the Zuid-
Willemsvaart leaves Netherlands territory—did not always give
satisfaction, for the reason that, even at Hocht, the surface of
the Meuse sometimes fell to the level of the Zuid-Willemsvaart
and even lower, so that the feeding of the Zuid-Willemsvaart
from the Meuse became impracticable. Now, if it is realized,
in the first place, that the level of the Zuid-Willemsvaart was
raised in pursuance of Article III of the Treaty, and that the
reach thus raised extends as far as lock 18—in other words,
almost as far as the frontier of Netherlands North Brabant—
and that, in the second place, the Meuse between Hocht and
Kessenich or Maasbracht—places which are almost in line with
lock 18—has a fall of more than twenty metres, whereas the
Zuid-Willemsvaart does not begin to fall rapidly before lock
No. 12, which is in line with Venlo, it is manifest that the
Meuse below Maestricht is descending a valley, whereas the
Zuid-Willemsvaart, as far as lock 18, continues its course
entirely on the western plateau, and only falls gradually till it
reaches lock 12 in line with Venlo.

That, it appears, suffices to show that the idea of supplying
the Zuid-Willemsvaart below Maestricht with Meuse water
would not be very practical, except in the immediate vicinity
of the feeder.

Belgium was henceforward to receive a very satisfactory allow-
ance of Meuse water for her requirements in the Campine,
through the new and only lawful intake at Maestricht—as was
pointed out by M. Rogier in his statement of reasons. It has
already been mentioned that the volume of water which the
new feeder at Maestricht was to supply was normally ten cubic
metres per second, of which eight cubic metres were the fixed
quantity guaranteed to Belgium (Art. V).

The specification of the precise amount of water to be taken
from the Meuse—a provision which was in itself unusual—points
to the conclusion that, when it was laid down that the intake at
Maestricht was to be henceforward the only feeder for the
supply of Meuse water to canals situated below that town, the
granting of this monopoly to the new intake carried with it a
prohibition of all feeding at other places, whether by conduits,
by discharging culverts, by lock-water or by any other means
by which Meuse water might be introduced into canals situated
below Maestricht.

This conclusion has been disputed in regard to a single
method of introducing Meuse water into canals situated below
Maestricht, namely the discharge of water by lockage. I con-
sider that this exception should not be allowed.

8 59
,

A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 60

À justification of the exception has been sought in the fact,
already mentioned, that the Treaty of 1863 makes no mention
of the quantities of water entering the Zuid-Willemsvaart by
the functioning of lock 19, which discharges into the Zuid-Wil-
lemsvaart a certain quantity of Meuse water that has been
conveyed from Liége by the Liége-Maestricht Canal; it has
been inferred from this fact that any quantity of water supplied
to canals situated below Maestricht by lockage, for instance
by the functioning of the Neerhaeren or Bosscheveld Locks,
would consequently be consistent with the Treaty of 1863.

I do not believe that this interpretation of the Treaty is cor-
rect. For the silence of the Treaty concerning the introduction
of the very small quantity of Meuse water which finds its way
into the canals below Maestricht by the functioning of lock 19
can be easily explained. As has been pointed out, the feeding
of the Zuid-Willemsvaart itself with Meuse water had not occa-
sioned any difficulty. Why should it have been otherwise when
the canal was prolonged to Liége? The silence of the texts
concerning the small quantities of Meuse water required for
navigation in the canal which linked Liége to the Meuse below
Bois-le-Duc is therefore quite comprehensible, both in the case of
the Treaty of 1845, concerning the prolongation of the Zuid-
Willemsvaart to Liége, and in the case of the Treaty of 1863,
which has restored the Liége-Maestricht Canal to its exclusive
rôle as a navigable waterway.

On the other hand, the immense quantities of Meuse water
which now enter the canals below Maestricht through the
modern locks at Neerhaeren and Bosscheveld, though the dis-
charge of the river has not altered, disturb the system of the
Treaty of 1863. That Treaty aimed at providing Belgium with
eight cubic metres of Meuse water per second, neither more
nor less. But by the functioning of the locks at Neerhaeren
and Bosscheveld, Belgium receives a far larger quantity. More-
over, every cubic metre per second passing through the lock
at Neerhaeren diminishes the quantity of supplementary water
which the Netherlands have a right to introduce through the
feeder at Maestricht, in virtue of Article V, paragraph 2, of
the Treaty; that right is limited by the maximum velocity of the
current specified in that Article, a velocity which is enhanced
by the lock-water discharged at Neerhaeren. Nay, more: the
Treaty of 1863 seeks to ensure that the Meuse water used for
supplying canals situated below Maestricht shall be taken solely
through the feeder at Maestricht, which is operated by the
Netherlands Waterstaat. It is easy to verify the quantities of
water diverted at a single intake, whereas it is difficult to
make such measurements when the water is drawn off at
different places, as used to happen before 1863. The intro-
duction of great quantities of water into the canals below

60
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 61

Maestricht by the functioning of large modern locks conse-
quently destroys the system of the Treaty of 1863 in another
sense also, for it puts an end to the monopoly of the intake at
Maestricht, and makes it very difficult to check the amount of
water diverted from the river by the Neerhaeren Lock, which
is not under the same administration as the intake at Maes-
tricht. It should be added that engineers agree in recognizing
that the principal method of supplying water to canals is,
precisely, by the functioning of the locks.

The expression ‘‘canals situated below Maestricht’’ is clear.
It refers, in addition to the Zuid-Willemsvaart and its branch
canals in Netherlands territory, to the Meuse-Scheldt Junction
Canal, which branches off at Bocholt on the Zuid-Willemsvaart
and terminates at Antwerp, and to its branches, and also to
the Turnhout Canal which runs via Saint Job to Antwerp.
The statement of reasons submitted by the Prime Minister,
M. Rogier, clearly alludes to this Campine system of canals
when he says that “the [Belgian] State obtains, for its part,
the possibility of feeding, not only the existing canals in the
Campine, but also the canal, the construction of which has
been decreed, from Turnhout via Saint Job to Antwerp”’.

It does not follow from the monopoly accorded to the intake
at Maestricht that the canals situated below that town and
the irrigation works in the Campine and the Netherlands may
not be fed from water-courses other than the Meuse. Such a
means of supply—as, for imstance, by the river Demer—is
perfectly compatible with the Treaty, and the only exception,
m this respect, is constituted by Article VII of the Treaty,
which lays down that the Belgian Government will leave undis-
turbed, or will restore to their natural courses, the streams
and water-courses which rise in Belgium and flow towards the
Netherlands territory. The fact that these canals or sectors
of canals are fed by other water-courses does not deprive them
of their character as canals situated below Maestricht, within
the meaning of Article I.

The intakes on the Meuse which are to be replaced, in pur-
suance of Article I, by the feeder at Maestricht (statement of
reasons by M. Rogier), are the three intakes which I have
referred to above. The intake, or rather the cascade, to the
left of lock 19 was, of course, to disappear with the disappear-
ance of that lock, which was abolished by Article IT of the
Treaty. As regards the important intake at Liége, the Belgian
Government made no difficulty on that point (Netherlands
Reply, pp. 42 and 43), and once the new system had been
instituted, only the quantities of water necessary to offset
lockage, leakage and evaporation were diverted at Liége. The
dismantling of the intake at Hocht, to the right of lock 109,
was not accepted so easily by Belgium. On the contrary, the

61
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 62

Belgian Government made a strong stand for the maintenance
of this intake in Belgian territory below Maestricht, and it is
quite comprehensible that, when it at last consented to its
being put out of operation, this point should have been recorded
in the Treaty. But the words “in consequence of the fore-
going’, at the beginning of the last paragraph of Article IV,
show clearly that the elimination of the Hocht intake was also
the logical consequence of the fact that, under Article I, the:
feeder at Maestricht was henceforward to be the only installa-
tion for supplying Meuse water to all the canals situated below
Maestricht and to the irrigation works in the Campine and in
the Netherlands.

The new régime for the diversion of water from the Meuse
necessitated certain changes in the Zuid-Willemsvaart, among
others the transfer, as already mentioned, of lock 19 to a situation
above the new feeder. These changes are set out in Articles II
and III. Moreover, the maintenance of a constant depth in
the Meuse, which had been disturbed by the considerable diver-
sions of water at the Liége and Hocht intakes (see statement
of reasons by M. Rogier)—which intakes were now to be replaced
by the feeder at Maestricht—made it necessary to undertake
certain works in the Meuse; these works are indicated in
Article IX and its Annexes.

The replacement of the different intakes which Belgium had
operated on the Meuse, by a single intake, namely, that of
Maestricht, which was henceforward to be the only ‘“tap”, would
have the great technical advantage, among others, of making
it possible to measure, at a single place, the volume of Meuse
water laid down in Article IV of the Treaty. That was an
advantage to which the attention of Belgium had been drawn,
inter alia, by the Minister of the Netherlands at Brussels in
1862 (Netherlands Memorial, p. 45).

It is clear that the substitution of a single intake, in Nether-
lands territory, for the different intakes on the Meuse which
were in Belgian territory constitutes a very real “de facto
advantage’”’ (see the oral statement of M. de Ruelle, the Belgian
Agent, p. 134) for the Netherlands. For “the country in which
the intake is situated enjoys, in practice, better opportunities
of supervision than the other country” (Belgian Rejoinder,
p. 6). That advantage is illustrated by the very strong resist-
ance offered by Belgium to the dismantling of the intake—that
of Hocht to the right of the old lock 19. This opposition is
constantly referred to in the despatches addressed to The Hague
in October 1862 by the Netherlands Minister at Brussels (see
Netherlands Memorial, pp. 43-48); and it is also apparent in
the Belgian proposals of February roth, 1863 (Netherlands

Reply, pp. 42-43).

62
A./B. 70 (WATER FROM THE MEUSE),—OP. VAN EYSINGA 63

The very tangible de facto advantage which the Netherlands
gained by the substitution of a single intake in Netherlands
territory for the different intakes on the Meuse in Belgian
territory—a substitution which was effected in virtue of Article I
of the Treaty of 1863—has been described by the Netherlands
as a right of “ascertaining (contrôler) at any moment that the
quantities of water taken from the Meuse do not exceed the quan-
tities specified in the Treaty, so that the complaints and discus-
sions of the past might be avoided’”’ (Netherlands Memorial, p. 8).

The question of control calls for the following observations.

Every international convention, unless it expressly excludes
it, implies a control by the contracting parties to see whether
the convention is being strictly applied. This control may lead
among other things to diplomatic representations and, if neces-
sary, to legal proceedings.

Thus, Belgium, when she thought that the Netherlands draft
law submitted to the States-General on February 7th, 1027,
and providing inter alia for the Borgharen barrage, involved
consequences at variance with the Treaties of May rath, 1863,
and January rith, 1873, addressed a note on the matter to
the Netherlands Government dated April 28th, 1921 (Belgian
Counter-Memorial, p. 27). Belgium was by this means exer-
cising her right of control over the Netherlands in regard to a
projected hydraulic installation on Netherlands territory, a right
of control which in the present case found concrete expression
in proceedings instituted against the Netherlands before the
Permanent Court of International Justice.

The right of control is in principle mutual or, more strictly
speaking, it is mutual wherever the convention is mutual. Thus
Belgium may and, as explained to the Court, does effectively
control the discharge by the Netherlands through the Maes-
tricht feeder of the quantities of water prescribed by the 1863
Treaty. But the Netherlands cannot exercise the same con-
trol over Belgium, because the Treaty provides for no intake in
Belgium.

On the other hand, each country may control the other when
it finds that the latter has constructed in its territory hydraulic
works whereby the canals situated below Maestricht will
receive more water than the Treaty prescribed. In this way,
Belgium exercised control over the Borgharen barrage and the
Netherlands over the lock at Neerhaeren.

The Netherlands undoubtedly have the right of control regard-
ing the culverts at the Neerhaeren Lock. The question whether
such culverts are in accordance with a treaty which abolished

63
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 64.

all the intakes in Belgian territory existing in 1863 and replaced
them by a single intake on Netherlands territory, is certainly
worth the attention of the Netherlands Government, especially as
hydraulic works of this kind are not built unless it is intended
that they should be used.

I consider, however, that the Netherlands argument goes too
far when it claims that, while the construction by Belgium of
works making it possible to feed a canal below Maestricht with
water taken from the Meuse elsewhere than at that town is
contrary to the 1863 Treaty, Belgium has no right to complain
of the construction of such works by the Netherlands. I do
not consider that the Netherlands Agent succeeded in proving
that the Netherlands here possess a right not possessed by
Belgium. I would add that this is the only point respecting
which the Netherlands have claimed a unilateral right of control.

The fact that the Netherlands Agent stressed at length. this
special right of control by the Netherlands has not helped to
clarify matters.

Nor did it help towards a better understanding of the case
when the Belgian defence ascribed to this Netherlands right
of control an extent which the Netherlands did not claim for it.

I notice in this connection that the Netherlands Government
stated that, by the transfer of the intake to Netherlands terri-
tory, it was thenceforth in a position to satisfy itself (contréler)
at any moment that the volume of water diverted from the
Meuse did not exceed the amounts prescribed in the Treaty,
so that the complaints and discussions which took place in the
past could be avoided (see above). It is therefore a question
of check on the quantities of water, and nothing more. But
the Belgian Government thinks that it involves a great deal
more than that.

Thus Belgium deduces from the indisputable fact that the
negotiations concerning the diversion of water from the Meuse
had been combined with those concerning the redemption
of the Scheldt tolls, the following argument, which appears
on page 6 of the Belgian Counter-Memorial: “The Nether-
lands possessed, in virtue of the Scheldt tolls, control of navi-
gation on the maritime part of the Scheldt. It was an impor-
tant prerogative; they were only willing to relinquish it—
such is the argument—in return for the control of navigation
on the canals which are now under discussion.” That is not
the correct way of stating the question. The Netherlands cer-
tainly do not claim that Article I of the Treaty of 1863
invested them with the control of navigation on the canals
situated below Maestricht. What the Netherlands say that

64
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 65

they acquired in virtue of Article I is simply the control over
the volume of water. Furthermore, if the Scheldt tolls really
conferred a right of control over navigation in the maritime
part of the Scheldt, as the Belgian Government seems to believe,
the navigation dues levied by Belgium on the Meuse (in the
case of the Netherlands these dues were abolished in 1851)
would constitute a Belgian right of control over navigation
on the Meuse. Would that really be in line with the Belgian
Government’s ideas ?

The Netherlands Government stated in its Application (p. 8)
that “The equilibrium established by the Treaty of 1863
between the interests affected has been disturbed by the under-
taking of these works, by the uses to which they are being
put and by the uses for which they are intended.” It is
clear from the manner in which this statement is developed
under (a), (b) and (c), that what was complained of was a
disturbance of the equilibrium in regard to the distribution of
the Meuse water as regulated once and for all in 1863. But
the Belgian Government interprets this statement in the Nether-
lands Application, although it is quite clear, as if it referred
to the economic equilibrium between Antwerp and Rotterdam
(see Belgian Counter-Memorial, p.

I might quote other extracts from the Belgian documents
and oral statements, but these two passages are sufficient to
show that Belgium regarded the control over the volume of
water as a control over navigation and traffic such as the
Netherlands have not claimed.

Before dealing with the Netherlands submission I a, I would
repeat that this is the only submission which the Netherlands
base upon this right of control and that, in particular, the
Netherlands defence against the Belgian counter-claim is not
founded upon this special right of control.

*
* *

In this submission I @ the Netherlands ask the Court to
declare that the construction by Belgium of works enabling a
canal situated below Maestricht to be supplied with water taken
from the Meuse elsewhere than at that town is contrary to the
Treaty of May 12th, 1863.

What is envisaged in this submission are works which, though
they do not at present feed a canal situated below Maestricht,
nevertheless enable this supply to be effected. In order to
confine our consideration to the kind of hydraulic works which
come into question in the present case, we should note that
what is envisaged is not longitudinal culverts in locks which it
is admitted will be utilized in addition to locking operations

65
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 66

(as is the case with the five locks of the Albert Canal between
the first lock near Herstal (Liége) and the last lock at Wyne-
ghem). Nor are we here envisaging locks which, as the Parties
are also agreed, will be utilized and consequently will dis-
charge lock-water.

We are solely concerned with works which might supply feed
water if they were utilized, as, for example, the longitudinal
culverts in the lock at Neerhaeren.

What attitude did Belgium adopt towards the Netherlands
submission I a ?

I should have understood it if Belgium, on the basis of her
interpretation of the 1863 Treaty, had said that, since the
Treaty does not apply above Maestricht, she was entitled to
discharge Meuse water through the Neerhaeren culverts into the
canals situated below Maestricht, and that she would make such
use of that right as she thought necessary. |

That however was not her attitude. The culverts having
been constructed, the Counter-Memorial on pages 10 and 1x
denies their existence, and when the Netherlands had demon-
strated that the Neerhaeren Lock was indeed provided with
culverts, Belgium fell back on the assertion that the electric
installations of the lock would only allow these culverts to be
used for filling the lock chamber (Oral Pleadings, p. 111). How-
ever, when the Netherlands Agent stated that this electrical
installation could be altered in five minutes (Oral Pleadings,
p. 171), that statement was not contradicted.

The question arises whether such an attitude stops short of
the line dividing what States may do from what they may not
do if they wish to remain within the law. I cannot answer
this question in the affirmative, and the submission under I a
appears therefore to be justified.

I would add that the Belgian Counsels ended by admitting
that in certain eventualities the culverts at the Neerhaeren
Lock would be used for some other purpose than lockage, which
indeed is not surprising, since culverts are not built except to
be used. It was rather a question of economic or military
necessity which would compel Belgium to keep intact the water
supply of the Zuid-Willemsvaart and of the inundation zones
which might be created north of Neerhaeren (Oral Pleadings,
pp. 91 and 210-211). .

In its submission under I 6, the Netherlands Government
asks the Court to declare that the feeding of the Belgian sec-
tion of the Zuid-Willemsvaart, of the Campine Canal, of the
Hasselt branch of that canal, and of the branch leading to
Beverloo Camp, as also of the Turnhout Canal, through the

66
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 67

Neerhaeren Lock, with water taken from the Meuse elsewhere
than at Maestricht, is contrary to the 1863 Treaty.

After what has already been said in the present note, not
much need be added.

It is common ground that the Treaty of 1863 defines and
limits the quantity of Meuse water to be used for feeding the.
Belgian system of Campine canals, and it is also common
ground that the feeder at Maestricht is to be the only feeder.
The cubic metre per second which is added by the lockage at
Neerhaeren is therefore contrary to the Treaty of 1863.

As already mentioned above, there is another reason why
the discharge of lock-water, which goes to feed the Zuid-
Willemsvaart, is contrary to the Treaty of 1863. This dis-
charge restricts the right reserved to the Netherlands by
paragraph 2 of Article V to increase the volume of water
drawn from the Meuse at Maestricht. The lockage at Neer-
haeren diminishes the right to increase the two cubic metres
per second allowed to the Netherlands under paragraph x of
Article V, by about one cubic metre per second.

In its submissions I c and I d, the Netherlands Government
asks the Court to declare that Belgium’s project of feeding a
section of the Hasselt Canal with water taken from the Meuse
elsewhere than at Maestricht is contrary to the Treaty of 1863,
and that Belgium’s project of feeding the section of the canal
joining the Zuid-Willemsvaart and the Scheldt between Heren-
thals (Viersel) and Antwerp with water taken from the Meuse
elsewhere than at Maestricht, is also contrary to the said
Treaty.

These two submissions can be examined in conjunction, as
they are very similar.

The Netherlands do not allege that Belgium would not be
entitled to enlarge the canals situated below Maestricht or to
change their names. In point of fact, Belgium has considerably
enlarged, not only the Zuid-Willemsvaart, but also parts of
the system of the Belgian Campine canals, in particular the
Meuse-Scheldt Junction Canal and the Hasselt branch. But, in
enlarging these canals, Belgium is not entitled to exempt them
from the rules governing their supply with Meuse water, which
are laid down in the Treaty of 1863. It is common ground
that the Treaty of 1863 lays down eight cubic metres per
second as the volume to be taken through the feeder at
Maestricht for this purpose. It is also-agreed that the sector
of the canal linking the Zuid-Willemsvaart with the Scheldt
between Herenthals (Viersel) and Antwerp will also receive
Meuse water through the Albert Canal, which, as far as lock No. I,
stands at a level of 60 and then falls more than 50 metres by
locks I to V before reaching Herenthais, and all these locks
are provided with discharging culverts which, it is admitted,

9 | 67
A./B. 70 (WATER FROM THE MEUSE).—-OP. VAN EYSINGA 68

will be utilized for feeding the different reaches of the canal.
It follows from the above that the feeding of this sector in
the manner projected will be contrary to the Treaty of 1863.

The same applies to the section of the Hasselt Canal which
is now being enlarged and will also form part of the Albert
Canal. The Netherlands do not contest Belgium’s right to feed
this section of the Hasselt Canal with water from the Demer.
The question of fact on which the two Governments differ is
whether this section, in addition to the water which it receives
from the Demer, is also fed by Meuse water coming from the
feeder at Maestricht and conveyed beyond Quaedmechelen by
the northern section of the Hasselt Canal. It appears that this
question of fact can be left on one side. But it seems clear
to me that this is a case of a canal situated below Maestricht,
one of the already existing canals in the Campine mentioned
in the statement of reasons drawn up by the Prime Minister,
M. Rogier, and that in consequence this canal may only receive
Meuse water derived through the feeder at Maestricht. It is.
also common ground that this enlarged portion of the canals.
situated below Maestricht will henceforward receive Meuse water
derived from Monsin ; hence the projected feeding of this section
with water diverted from the Meuse elsewhere than at Maestricht
will be contrary to the Treaty of 1863.

The Belgian Agent said on page 14 of the Counter-Memorial
that, if the Albert Canal from Pulle onwards, instead of being
linked with the canal uniting the Meuse and the Scheldt, had
been placed alongside it, separated from it by a dyke which
prevented the waters from mixing, the charge made by the
Netherlands would never have been brought. That is true,
but it is true also that this hypothetical contingency did not
arise and that, once the Albert Canal were completed, the canals
situated below Maestricht, apart from the Neerhaeren Lock,
will be fed with Meuse water not coming from the Maestricht
feeder. I would add that the Netherlands Agent, replying to
the above-mentioned remark of his Belgian colleague, said that
if Belgium had constructed other works than she has, the
Netherlands complaints would certainly have taken another
form and been furnished with a very different legal basis
(Netherlands Reply, p. 24).

*
* %

With regard to the counter-claim, I need only make the
following observations :

It is clear from pages 26, 27 and 29 of the Netherlands Reply
that, as regards both the Borgharen barrage and the Bossche-
veld Lock and Juliana Canal, the Netherlands defence rests
upon Article V, paragraph 2, of the 1863 Treaty.

68
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 69

And the oral statement of the Netherlands Agent (Oral
Pleadings, pp. 52-69) has the same foundation.

The Netherlands defence begins on page 52 with the following
sentence: “The points at issue in the case submitted to the
Court through the Belgian counter-claim are three in number ;
but they have a common basis, or rather our defence.is based
upon a single point of law. I want first to discuss this common
point of law: it is the question of the distribution of water and of
Article V, paragraph 2, of the Treaty.” Pages 52-62 are almost
entirely devoted to the interpretation of Article V, paragraph 2,
and pages 62-69 then apply this interpretation to the three
hydraulic installations impugned in the counter-claim. On
pages 62 and 67 the Netherlands Agent again says that his
defence against the counter-claim rests upon Article V, para-
. graph 2, of the Treaty of 1863.

One would search the Netherlands defence against the counter-
claim in vain to find any allusion to the right of control, which,
as already mentioned above, serves as the basis of the Nether-
lands submission I @ only.

The Netherlands interpretation of paragraph 2 of Article V
of the 1863 Treaty may, I think, be summarized as follows.

This provision allows, or rather it presupposes, that the
Netherlands are free to withdraw water from the Meuse below
Maestricht. Any interpretation which restricted this freedom
would be vexatious and therefore inadmissible. Article V, para-
graph 2, deals only with the case in which the Netherlands
should decide to divert quantities of water from the Meuse
into the Maestricht feeder in addition to the quantity. laid
down in Article IV and Article V, paragraph 1: only in this case
is the additional water to pass into the Netherlands through
lock No. 17 at Loozen.

The mere right to divert additional water into the Zuid-
Willemsvaart allows the Netherlands to put the Meuse constantly
out of use for an average of more than a hundred days in the
year. This implies that Belgium, by accepting the Treaty of
1863, left the navigability of the frontier section of the Meuse
to the discretion of the Netherlands, Belgium, so to speak,
abandoning the interests of navigation over that part of the
Meuse to the care of the Netherlands.

The freedom enjoyed by the Netherlands of taking water from
the Meuse below Maestricht, a right which Belgium admitted
when she disclaimed interest in navigation over the frontier section
of the Meuse through her acceptance of Article V, paragraph 2,
allows the Netherlands, on the one hand, to feed the Juliana
Canal with Meuse water and, on the other, to make a present
to Belgium of certain quantities of water from the Meuse,

69
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 70

which they do. through the operation both of the Borgharen
barrage and of the Bosscheveld Lock.

It follows from the above that the feeding of the Zuid-
Willemsvaart as the result of the Borgharen barrage and the
functioning of the Bosscheveld Lock, and also the feeding of
the Juliana Canal with water from the Meuse, are, according
to the Netherlands case, permissible under Article V, para-
graph 2, of the Treaty of 1863. .

I am of opinion that Article V, paragraph 2, does not pos-
sess the very wide scope given to it by the Netherlands case,
and that some of the consequences which that argument seeks
to deduce therefrom are not justified.

The Treaty of 1863 confines itself to regulating the supply
with Meuse water of the canals situated below Maestricht and
of the irrigation channels of the Campine and the Netherlands
(Art. I). The waterways in question are therefore the Zuid-
Willemsvaart and the canals and irrigation channels branching
from it. Though, under Article V, paragraph 2, the Nether-
lands are entitled to increase the volume of water assigned to
them by the first paragraph of Article V, that additional water
must be necessary for canals situated below Maestricht or for
irrigation in the Netherlands. The water must also pass through
the Maestricht feeder, the exclusive use of which is incumbent
both upon Belgium and upon the Netherlands, although, as
mentioned above, its practical value below Maestricht is limited
to the immediate neighbourhood of that town; the very gen-
eral wording of Article I is clear on this point. The last phrase
in paragraph’ 2 of Article V imposes upon Belgium the duty
of delivering to the Netherlands the additional water taken at
Maestricht in virtue of the first phrase in that paragraph.

Applying my interpretation to the points at issue in the
counter-claim, I reach the following result.

The feeding of the .Zuid-Willemsvaart with water from the
working of the Bosscheveld Lock remains within the limits
fixed by paragraph 2 of Article V, so far as concerns the speed
of the current in the Zuid-Willemsvaart. There is however a
departure from the Treaty in the fact that the additional
water, lawful in itself, if needed for the Netherlands canals
below Maestricht or for Netherlands irrigation, does not pass
through the treaty feeder. The departure is certainly of smaller
extent than between the Treaty and the use of the lock-water
at Neerhaeren, which, unlawful in itself, diminishes the right
possessed by the Netherlands under paragraph 2 of Article V,
while the measurement of the volume of water withdrawn from
the Meuse is rendered difficult since it cannot be effected by
the same administration.

70
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 71

As we know, the lock-water discharged by the Bosscheveld
Lock is not the subject of a submission in the Belgian counter-
claim.

The additional water which at certain seasons of the year
passes through the Maestricht feeder as the result of the raising
of the level of the Meuse—itself the consequence of the
Borgharen barrage—has nothing to do with Article V, para-
graph 2, of the Treaty.

This water is part of the quantities laid down in Article IV
and secures for the Zuid-Willemsvaart a permanent flow of ten
cubic metrés per second, which the Belgian Minister for Foreign
Affairs, in his note of January 22nd, 1912 (Netherlands Reply,
p. 72), thought indispensable to feed the canals from Liége
to Antwerp. I do not see why this state of affairs should have
made it impossible to apply the Treaty regularly, as Belgium
asserts it has, all the less so because, even in 1863, the Meuse
régime was characterized by a number of barrages with locks
constructed both by France and by Belgium in the absence of
any international agreement. Had it been intended to deny
to the Netherlands a right which the other riparian States of
the Meuse claimed to possess, the Treaty of 1863 would have
made it clear. For my part, I hold that the Borgharen bar-
rage was not constructed contrary to the terms of this Treaty.

As stated above, the Treaty of 1863 confines itself to regu-
lating the supply of the Zuid-Willemsvaart and of a number of
navigation and irrigation channels, all of which are situated on
the left bank of the river. The Juliana Canal, on the right
bank of the Meuse, below the Maestricht feeder, the working
of which it cannot affect, accordingly lies outside the sphere of
the Treaty of 1863. That Treaty cannot therefore either allow
the Juliana Canal to be fed with Meuse water, as maintained
by the Netherlands, or forbid it so to be fed, as maintained by
Belgium. The question of the feeding of the Juliana Canal
with water from the Meuse is thus not touched upon by the
Treaty of 1863.

Lastly, the Netherlands seek to deduce from paragraph 2 of
Article V that Belgium by that Article disclaimed all interest
in navigation over the frontier section of the Meuse, this navi-
gation being left to the discretion of the Netherlands. This
deduction is not I think justified.

It is true that, when the flow of the river is at its mini-
mum, the joint section of the Meuse may almost run dry for
the reason that the Maestricht feeder must function at all
times. But if there were no intakes on the Meuse, the river,
even if it were not completely dry, would for considerable periods
have so little water that navigation would then too be out of

71
A./B. 70 (WATER FROM THE MEUSE).—OP. VAN EYSINGA 72

‘the question. Nevertheless, Belgian interest in that navigation
would remain the same. That interest is the direct result of
the fact that Belgium is a riparian State, and it is not limited
to the joint section of the Meuse only, but extends to the
whole river. |

The fact that Belgium is a riparian State furnishes a much
stronger ground for Belgium’s interest in navigation over the
“whole Meuse than does Article IX of the Treaty, quite apart
from the fact that this Article is limited to the part of the
river between Maestricht and Venlo. Under Article IX, Belgium
undertook to pay two-thirds of the cost of regularizing
the Meuse between Maestricht and Venlo, since this work was
necessary to counteract the mischievous consequences to river
navigation of withdrawing large quantities of water for Belgium.
It is compensation which Belgium would have had to pay even if
she had really disclaimed all interest in Meuse navigation below
Maestricht. The Counter-Memorial describes the situation very ~
well when it says on page 5 that Belgium to a certain extent
purchased the water taken at Maestricht for the canals of
the Campine. Article IX of the 1863 Treaty does not prove the
interest of Belgium in navigation on the joint section of the
Meuse. That interest, whether great or small, exists by the
mere fact that Belgium is a riparian State.

(Signed) v. EYSINGA.

72


                                                                                393

                                   Déclaration de M. le juge Keith

                    [Traduction]

                       1. Je souscris aux conclusions de la Cour, et ce, essentiellement pour
                    les motifs exposés dans l’arrêt. La présente déclaration porte uniquement
                    sur l’un des aspects du raisonnement suivi.
                       2. Depuis près de quatre-vingt-dix ans, la Cour — qu’il s’agisse de la
                    Cour internationale de Justice ou de sa devancière, la Cour permanente
                    de Justice internationale — a la faculté d’autoriser un Etat non partie à
                    une procédure principale dont elle est saisie à intervenir à l’instance, dès
                    lors que celui‑ci parvient à démontrer qu’« un intérêt d’ordre juridique est
                    pour lui en cause » (article 62 du Statut). L’Etat ainsi admis à intervenir
                    reçoit copie des pièces de procédure et peut, sur l’objet de l’intervention,
                    présenter à la Cour une déclaration écrite, puis, au cours de la procédure
                    orale, des observations (article 85 du Règlement). Sur les quinze requêtes
                    à fin d’intervention soumises depuis 1923 dans douze affaires, deux ont
                    été admises, l’une dans sa totalité, l’autre en partie seulement.
                       3. Jusqu’à aujourd’hui, la Cour n’avait pas cherché à expliciter l’expres-
                    sion « intérêt d’ordre juridique » telle qu’elle figure à l’article 62 du Statut,
                    se contentant, après examen des éléments de preuve et des conclusions pré-
                    sentés par l’Etat demandant à intervenir et les parties à la procédure prin-
                    cipale, de déterminer si, « concrètement et … par rapport à toutes les
                    circonstances de l’espèce », l’Etat en question avait démontré ce qu’il avan-
                    çait, et notamment que son intérêt pouvait être affecté par la décision
                    qu’elle rendrait (Différend frontalier terrestre, insulaire et maritime (El Sal‑
                    vador/Honduras), requête à fin d’intervention, arrêt, C.I.J. Recueil 1990,
                    p. 117‑118, par. 61).
                       4. C’est pour de bonnes raisons, selon moi, que la Cour s’en est jusqu’à
                    présent strictement tenue au critère énoncé à l’article 62 du Statut, sans
                    chercher à en interpréter une expression isolée. Je m’intéresserai tout
                    d’abord à la nature du pouvoir exercé par la Cour en vertu de l’article 62.
                    Ce pouvoir revêt un caractère préliminaire, procédural et interlocutoire.
                    En matière d’effet juridique ou de force obligatoire, il s’agit simplement
                    d’autoriser (ou non) l’Etat demandant à intervenir à prendre part à l’ins-
                    tance. Dans cette optique, la Cour doit se livrer à une appréciation, de
                    nature spéculative et prospective, de l’incidence que pourrait avoir la
                    décision qu’elle rendra dans la procédure principale sur l’intérêt que pré-
                    tend détenir l’Etat demandant à intervenir. La question est de savoir si
                    cette décision « peut » affecter cet intérêt, et non si elle l’affectera « effecti-
                    vement » ou « vraisemblablement ».
                       5. Les principales caractéristiques du pouvoir qu’a la Cour de rendre
                    sa décision en la procédure principale diffèrent nettement de celles du
                    pouvoir qu’elle tient de l’article 62. Dans le premier cas, les parties ont

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                                différend territorial et maritime (décl. keith)                  394

                    largement plus de possibilités de plaider leur cause, tant à l’écrit qu’à
                    l’oral, et de répondre aux arguments qui leur sont opposés ; elles doivent
                    avoir consenti, d’une manière ou d’une autre, à la compétence de la Cour
                    pour connaître de l’affaire ; la Cour rend une décision définitive au fond,
                    qui est obligatoire pour les parties et sans recours. En procédant de la
                    sorte, elle détermine si tels ou tels droits existent et s’ils ont été violés, son
                    constat relevant d’un processus qui est en général de nature rétrospective.
                    De plus, il incombe normalement à la partie qui avance un fait à l’appui
                    de sa thèse de l’établir à l’aune du critère de la plus forte probabilité,
                    condition nettement plus exigeante que celle énoncée à l’article 62.
                        6. Si, parmi les différences entre les deux fonctions, figure effectivement
                    une distinction entre « droit » (juridique) et « intérêt d’ordre juridique »,
                    les deux paragraphes précédents donnent cependant à penser qu’elle ne
                    joue qu’un rôle mineur. La définition que donne la Cour de l’« intérêt
                    d’ordre juridique » montre que cette distinction n’est pas sans poser pro-
                    blème, et de même les conséquences que la Cour y attache. Celle‑ci, en
                    effet, définit aujourd’hui l’« intérêt d’ordre juridique » comme « une préten-
                    tion concrète et réelle … fondée sur le droit » par opposition au « droit
                     établi » (arrêt (requête du Costa Rica à fin d’intervention), par. 26 ; arrêt
                    (requête du Honduras à fin d’intervention), par. 37) ; or, si la prétention est
                    juridiquement fondée et si elle est réelle et concrète, ne s’agit‑il pas de la
                    revendication d’un droit (ou d’une liberté ou d’un pouvoir) juridiquement
                    reconnu ? On peut donc se demander si la Cour opère une véritable
                    distinction.
                        7. Quant aux conséquences que la Cour attache à sa définition, elles
                     sont au nombre de deux : d’une part, le droit établi jouit d’une protection
                     supérieure et, d’autre part, les exigences en matière de preuve ne sont pas
                     aussi strictes en ce qui concerne l’intérêt d’ordre juridique. Ces consé-
                     quences découlent cependant des caractéristiques propres aux deux pou-
                     voirs de la Cour dont les différences ont été exposées aux paragraphes 4
                     et 5 ci‑dessus, et non de la seule distinction qui existerait entre droit établi
                     et intérêt d’ordre juridique.
                        8. La pratique des Etats demandant à intervenir tend en outre à confir-
                     mer le caractère incertain de cette distinction, qui ne semble pas présenter
                     pour eux d’utilité. Ainsi, en l’espèce, le Costa Rica avait d’emblée indi-
                     qué, dans sa requête, que « les intérêts d’ordre juridique … pour lui en
                     cause [étaient] les droits souverains et la juridiction que le droit internatio-
                     nal reconna[issait] au Costa Rica et que celui‑ci revendiqu[ait] confor
                     mément à sa Constitution » (les italiques sont de moi). Il a, pour l’essen-
                     tiel, dit la même chose au terme de la procédure, dans sa réponse à une
                     question posée par l’un des membres de la Cour. De même, pour démon-
                     trer qu’il possédait un intérêt d’ordre juridique, le Honduras a affirmé
                     — ainsi que le relève la Cour dans son arrêt — avoir des droits souve-
                     rains et une juridiction à faire valoir sur une zone maritime donnée (arrêt,
                     par. 16 et 18).
                        9. Cette étroite association entre intérêts d’ordre juridique et droits
                     découlant du droit international n’est d’ailleurs pas récente :

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                    —	Dans l’affaire du Vapeur Wimbledon, la Pologne avait ainsi dans un
                      premier temps allégué « la violation … des droits et des intérêts [qui lui
                      étaient] garantis … par l’article 380 du traité [de Versailles] » ; ayant
                      ensuite modifié sa demande pour pouvoir se prévaloir de l’article 63, elle
                      fut admise à intervenir (Vapeur Wimbledon, arrêts, 1923, C.P.J.I. série
                      A no 1 (question de l’intervention de la Pologne), p. 13).
                    —	Dans sa requête à fin d’intervention dans les affaires des Essais nucléaires,
                      Fidji, ayant fait état des demandes formulées par l’Australie et la
                      Nouvelle‑Zélande — qui affirmaient, l’une, que les essais n’étaient pas
                       compatibles avec les règles applicables du droit international et, l’autre,
                       qu’ils constituaient une violation de ses droits au regard du droit
                       international —, soutenait que « les faits … exposés montr[aient] que le
                        comportement de la France [l’]affectait pour le moins autant que la
                        Nouvelle‑Zélande [ou l’Australie] et que des considérations juridiques
                        analogues s’appliqu[aient] à l’un et l’autre pays » (Essais nucléaires
                        (Nouvelle‑Zélande c. France), requête de Fidji à fin d’intervention, p. 10).
                        La Cour ne s’est toutefois pas prononcée sur le fond de cette demande
                        (Essais nucléaires (Nouvelle-Zélande c. France), requête à fin d’interven‑
                        tion, ordonnance du 20 décembre 1974, C.I.J. Recueil 1974, p. 536).
                    —	Dans l’affaire Tunisie/Libye, Malte, bien qu’ayant utilisé les termes de
                        l’article 62, spécifiait d’emblée que son « intérêt d’ordre juridique »
                        était constitué par des droits ou « titres » dérivés du droit :
                             « Il est hors de doute que l’intérêt de Malte quant aux limites de
                          son plateau continental est de nature juridique, puisque les titres des
                          Etats sur le plateau continental dérivent du droit, de même que les
                          principes et règles d’après lesquels les zones dont il s’agit sont défi-
                          nies et délimitées. En d’autres termes, ces titres sont créés et proté-
                          gés par le droit, et la question de la juste étendue spatiale des régions
                          où ils peuvent être exercés par un Etat déterminé est également une
                          question juridique. » (Plateau continental (Tunisie/Jamahiriya arabe
                          libyenne), requête de Malte à fin d’intervention, p. 5, par. 7.)

                    —	Dans l’affaire Libye/Malte, l’Italie, dans sa requête à fin d’intervention,
                      se référait de même, sous l’intitulé « L’« intérêt d’ordre juridique » », à
                      ce qu’elle considérait comme ses droits et son titre juridique sur des
                      portions de plateau continental au large de ses côtes, les zones
                      pertinentes se trouvant à moins de 400 milles marins de celles‑ci
                      (Plateau continental (Jamahiriya arabe libyenne/Malte), requête de
                      l’Italie à fin d’intervention, p. 5‑9, par. 6‑13).
                    —	Dans l’affaire El Salvador/Honduras, le Nicaragua présentait son
                      intervention comme ayant un objet double :
                             « Premièrement, … protéger généralement, par tous les moyens
                          juridiques possibles, les droits de la République du Nicaragua dans
                          le golfe de Fonseca et dans les espaces maritimes contigus.

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                          Deuxièmement, … intervenir dans l’instance pour informer la
                       Cour de la nature des droits du Nicaragua qui sont en cause dans le
                       litige. Cette forme d’intervention aurait un but conservatoire : elle
                       viserait à garantir que les conclusions de la Chambre ne portent pas
                       atteinte aux droits et intérêts de la République du Nicaragua, et le
                       Nicaragua entend reconnaître l’effet obligatoire de la décision qui
                       sera rendue. » (Différend frontalier terrestre, insulaire et maritime
                       (El Salvador/Honduras ; Nicaragua (intervenant)), requête du Nica-
                       ragua à fin d’intervention, p. 5, par. 5‑6.)

                 —	Dans l’affaire Cameroun c. Nigeria, la Guinée équatoriale, là encore
                   sous un intitulé reprenant les termes de l’article 62, rappelait ce que
                   la Cour avait dit dans son arrêt sur les exceptions préliminaires en
                   l’affaire, poursuivant ainsi en se référant au droit :
                          « En fait, de par son droit interne, la Guinée équatoriale reven-
                       dique une zone économique exclusive et une mer territoriale, en des
                       termes qu’elle considère comme conformes aux droits qu’elle tient du
                       droit international. La zone maritime qu’elle revendique se traduit
                       dans l’angle nord‑est du golfe de Guinée, sur la base du principe des
                       lignes médianes, par une frontière qui marquerait à la fois la limite de
                       sa zone économique exclusive et — dans certaines circonstances — la
                       limite de sa mer territoriale par rapport au Cameroun sur une dis-
                       tance limitée. » (Frontière terrestre et maritime entre le Cameroun et le
                       Nigéria (Cameroun c. Nigéria ; Guinée équatoriale (intervenant)),
                       requête de la Guinée équatoriale à fin d’intervention, p. 7‑9.)
                     Ayant précisé sa position en invoquant des dispositions spécifiques de
                     son droit interne, elle ajoutait :
                       « conformément à son droit national, la Guinée équatoriale reven-
                       dique les droits souverains et la juridiction que lui confère le droit
                       international jusqu’à la ligne médiane entre la Guinée équatoriale et
                       le Nigéria, d’une part, et entre la Guinée équatoriale et le Came-
                       roun, d’autre part. Ce sont ces droits et intérêts d’ordre juridique
                       que la Guinée équatoriale cherche à protéger. » (Ibid., p. 9.)
                 —	Dans l’affaire de la Demande d’examen de la situation au titre du
                   paragraphe 63 de l’arrêt rendu par la Cour le 20 décembre 1974 dans
                   l’affaire des Essais nucléaires (Nouvelle‑Zélande c. France), l’Australie
                   commençait par présenter, également sous un intitulé reprenant les
                   termes de l’article 62, deux revendications de la Nouvelle‑Zélande :
                          « Si, comme la Nouvelle‑Zélande le soutient, les droits … ont le
                       caractère erga omnes évoqué ci‑dessus, l’action intentée par la
                       Nouvelle‑Zélande contre la France met nécessairement en cause les
                        droits de tous les Etats, Australie comprise. Si la France est liée
                        par les obligations erga omnes correspondantes invoquées par la
                        Nouvelle‑Zélande (question qu’il appartiendra à la Cour de tran-

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                       cher lors de l’examen au fond), l’Australie a, en commun avec la
                       Nouvelle‑Zélande et tous les autres Etats, un « intérêt juridique »
                       [pour reprendre l’expression utilisée par la Cour dans l’affaire de
                       la Barcelona Traction] à ce que la France respecte ces obligations.
                          Comme on l’a indiqué ci‑dessus, la Nouvelle‑Zélande soutient
                       que ces obligations, « par leur nature même, valent à l’égard de l’en-
                       semble de la communauté internationale, et [qu’]il serait absurde de
                       les concevoir comme autant d’obligations qu’il faudrait honorer, à
                       titre bilatéral, à l’égard de chacun des membres de cette commu-
                       nauté… ». Si tel est le cas, il s’ensuit nécessairement qu’une décision
                       de la Cour sur le fond n’aurait pas pour objet les droits et devoirs
                       bilatéraux de la France et de la Nouvelle‑Zélande, considérés à part
                       des droits et devoirs bilatéraux identiques existant entre la France et
                       chacun des membres de la communauté internationale. » (Demande
                       d’examen de la situation au titre du paragraphe 63 de l’arrêt rendu par
                       la Cour le 20 décembre 1974 dans l’affaire des Essais nucléaires
                       (Nouvelle‑Zélande c. France), requête de l’Australie à fin d’interven-
                       tion en vertu de l’article 62, p. 9, par. 18‑19.)

                     Ici aussi, c’est sur des droits, tels que revendiqués par l’Australie,
                     qu’est fondée la demande d’intervention. L’on notera la référence à
                     l’« intérêt juridique », expression qui figure dans l’arrêt rendu en l’af-
                     faire de la Barcelona Traction ; elle renvoie à la faculté qu’a un Etat de
                     présenter une demande et non à la nature profonde du droit ou de
                     l’intérêt revendiqué, question apparemment distincte de l’« intérêt
                     d’ordre juridique » devant être apprécié dans le cadre de l’examen
                     d’une demande d’intervention.
                     Les Iles Salomon, les Etats fédérés de Micronésie, les Iles Marshall et
                     le Samoa avaient présenté des demandes d’intervention en des termes
                     similaires, invoquant l’article 63 ainsi que l’article 62. Dans le cadre
                     de ce dernier, ils faisaient valoir que « les différends relatifs à des
                     obligations erga omnes [avaient] une unité intrinsèque » (Demande
                      d’examen de la situation au titre du paragraphe 63 de l’arrêt rendu
                      par la Cour le 20 décembre 1974 dans l’affaire des Essais nucléaires
                      (Nouvelle‑Zélande c. France) : requête à fin d’intervention en vertu de
                      l’article 62 et déclaration d’intervention en vertu de l’article 63 pré
                      sentées par les Iles Salomon, p. 6, par. 19 ; requête à fin d’interven
                      tion en vertu de l’article 62 et déclaration d’intervention en vertu
                      de l’article 63 présentées par les Etats fédérés de Micronésie, p. 6,
                      par. 19 ; requête à fin d’intervention en vertu de l’article 62 et déclara-
                      tion d’intervention en vertu de l’article 63 présentées par les Iles
                      Marshall, p. 6, par. 19 ; requête à fin d’intervention en vertu de l’ar-
                      ticle 62 et déclaration d’intervention en vertu de l’article 63 présen-
                      tées par le Samoa, p. 6, par. 19).
                      La Cour ne s’est prononcée sur aucune des cinq requêtes présentées en
                      l’affaire (Demande d’examen de la situation au titre du paragraphe 63

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                   de l’arrêt rendu par la Cour le 20 décembre 1974 dans l’affaire des
                   Essais nucléaires (Nouvelle‑Zélande c. France), ordonnance du
                   22 septembre 1995, C.I.J. Recueil 1995, p. 306‑307, par. 67).
                 —	Dans l’affaire relative à la Souveraineté sur Pulau Ligitan et Pulau
                   Sipadan, les Philippines indiquaient que leur requête avait pour objet :
                       « a)	Premièrement, de préserver et sauvegarder les droits d’ordre
                            historique et juridique du Gouvernement de la République des
                            Philippines qui découlent de la revendication de possession et
                            de souveraineté que ce gouvernement forme sur le territoire du
                            Bornéo septentrional dans la mesure où ces droits sont ou
                            pourraient être mis en cause par une décision de la Cour rela-
                            tive à la question de la souveraineté sur Pulau Ligitan et Pulau
                            Sipadan.
                         b)	Deuxièmement, d’intervenir dans l’instance pour informer la
                            Cour de la nature et de la portée des droits d’ordre historique
                            et juridique de la République des Philippines qui pourraient être
                            mis en cause par la décision de la Cour. » (Souveraineté sur Pulau
                            Ligitan et Pulau Sipadan (Indonésie/Malaisie), requête des Phi-
                            lippines à fin d’intervention, p. 5, par. 5.)

                    10. J’en viens maintenant aux décisions de la Cour sur les demandes
                 d’intervention présentées en vertu de l’article 62, en commençant par
                 l’une des deux affaires en lesquelles la requête a été admise. Dans l’affaire
                 en question, le Nicaragua fut autorisé à intervenir pour ce qui concernait
                 le régime juridique des eaux du golfe de Fonseca. Le Honduras ne s’était
                 pas opposé à cet aspect de sa demande, considérant qu’un régime juri-
                 dique spécial était nécessaire en raison de la communauté d’intérêts entre
                 les Etats côtiers. La Chambre de la Cour, notant qu’El Salvador avait fait
                 valoir, dans le cadre de la procédure, que les eaux étaient soumises à un
                 condominium des trois Etats côtiers, admit la demande d’intervention
                 sur ce point (Différend frontalier terrestre, insulaire et maritime (El Salva‑
                 dor/Honduras), requête à fin d’intervention, arrêt, C.I.J. Recueil 1990,
                 p. 120‑122, par. 69‑72). Elle ne fit en revanche pas droit à la demande
                 relative à la délimitation maritime à l’intérieur et en dehors du golfe (ibid.,
                 p. 123‑128, par. 74‑84). Ce sont ces rejets qui sont significatifs aux fins des
                 présentes procédures. De même que dans les deux autres cas où des
                 demandes d’intervention n’ont pas été admises dans une affaire de délimi-
                 tation (Plateau continental (Tunisie/Jamahiriya arabe libyenne), requête à
                 fin d’intervention, arrêt, C.I.J. Recueil 1981, p. 20, par. 37 ; Plateau conti‑
                 nental (Jamahiriya arabe libyenne/Malte), requête à fin d’intervention,
                 arrêt, C.I.J. Recueil 1984, p. 26‑28, par. 42‑43 et 47), ces rejets sont à rat-
                 tacher à deux caractéristiques des décisions de la Cour en matière de déli-
                 mitation maritime. La première a été rappelée par la Chambre de la Cour
                 dans sa décision sur la demande d’intervention du Nicaragua (Différend
                 frontalier terrestre, insulaire et maritime (El Salvador/Honduras), requête
                 à fin d’intervention, arrêt, C.I.J. Recueil 1990, p. 124, par. 77) : les délimi-

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                  tations effectuées entre deux Etats — par voie conventionnelle aussi bien
                  qu’en vertu d’une décision d’une tierce partie, ajouterais‑je — prennent
                  souvent en compte les côtes d’un ou de plusieurs Etats. La seconde est
                  que la Cour, lorsqu’elle trace une ligne de délimitation, veille à ce
                  que celle-ci s’arrête avant de toucher les droits ou intérêts d’Etats tiers
                  (voir, par exemple, Plateau continental (         Tunisie/Jamahiriya arabe
                  libyenne), arrêt, C.I.J. Recueil 1982, p. 93‑94, par. 133 ; Plateau continen‑
                  tal (Jamahiriya arabe libyenne/Malte), arrêt, C.I.J. Recueil 1985, p. 25‑28,
                  par. 21‑22 ; Délimitation maritime et questions territoriales entre Qatar et
                 Bahreïn (Qatar c. Bahreïn), fond, arrêt, C.I.J. Recueil 2001, p. 115‑117,
                 par. 250‑252 ; Frontière terrestre et maritime entre le Cameroun et le
                 Nigéria (Cameroun c. Nigéria ; Guinée équatoriale (intervenant)), arrêt,
                  C.I.J. Recueil 2002, p. 448, par. 306‑307 ; Différend territorial et maritime
                  entre le Nicaragua et le Honduras dans la mer des Caraïbes (Nicaragua
                  c. Honduras), arrêt, C.I.J. Recueil 2007 (II), p. 756‑759, par. 312‑319 ;
                  Délimitation maritime en mer Noire (Roumanie c. Ukraine), arrêt,
                  C.I.J. Recueil 2009, p. 131, par. 219). Cette pratique semble bien montrer
                  que les parties communiquent à la Cour les informations pertinentes
                  concernant les intérêts d’Etats tiers, parfois, d’ailleurs, à l’appui d’une
                  exception d’incompétence ou d’irrecevabilité fondée sur le principe énoncé
                  dans l’affaire de l’Or monétaire (voir les écritures du Nigéria dans l’affaire
                  Cameroun c. Nigéria (Frontière terrestre et maritime entre le Cameroun
                  et le Nigéria (Cameroun c. Nigéria ; Guinée équatoriale (intervenant)),
                  exceptions préliminaires de la République fédérale du Nigéria,
                  par. 4.1‑4.11 et 8.11‑8.17) et celles du Nicaragua dans l’affaire El Salva‑
                  dor/Honduras (Différend frontalier terrestre, insulaire et maritime (El Sal‑
                  vador/Honduras ; Nicaragua (intervenant)), requête, p. 6‑7, par. 9‑12 ;
                  ibid., déclaration écrite, p. 3‑27)).
                      11. La seule requête à fin d’intervention admise dans une affaire de déli-
                  mitation maritime fut celle présentée par la Guinée équatoriale en l’affaire
                  Cameroun c. Nigeria (Frontière terrestre et maritime entre le Cameroun et le
                  Nigéria (Cameroun c. Nigéria), requête à fin d’intervention, ordonnance du
                  21 octobre 1999, C.I.J. Recueil 1999 (II), p. 1029). Plusieurs aspects de cette
                  décision limitent toutefois sa pertinence aux fins des présentes procédures :
                  en rejetant un argument fondé sur le principe de l’Or monétaire, la Cour
                  avait laissé entendre, dans son arrêt sur la compétence, que certains Etats
                  tiers pourraient souhaiter intervenir (Frontière terrestre et maritime entre le
                  Cameroun et le Nigéria (Cameroun c. Nigéria), exceptions préliminaires,
                  arrêt, C.I.J. Recueil 1998, p. 323‑324, par. 115‑116), mais seul l’un d’entre
                  eux, la Guinée équatoriale, présenta une demande en ce sens ; aucune ob
                  jection n’y fut faite et la requête fut admise en vertu d’une ordonnance
                  de la Cour et non d’un arrêt ; enfin, la Cour déclara, dans l’arrêt rendu
                  dans la procédure principale, qu’en établissant la frontière maritime elle
                  devait veiller à ne pas adopter une position susceptible d’affecter les droits
                   de la Guinée équatoriale et de Sao Tomé‑et‑Principe (Frontière terrestre
                   et maritime entre le Cameroun et le Nigéria (Cameroun c. Nigéria ; Gui
                   née équatoriale (intervenant)), arrêt, C.I.J. Recueil 2002, p. 421, par. 238).

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                 Sao Tomé‑et‑Principe, qui n’avait pas demandé à intervenir, se vit accorder
                 la même protection que l’Etat qui avait fait une demande en ce sens ; du
                 reste, c’est aux « droits » et non aux « intérêts » des deux Etats que la Cour
                 faisait référence (C.I.J. Recueil 2002, p. 421, par. 238).
                    12. Pour résumer, la distinction opérée par la Cour entre « droits dans
                 l’espèce considérée » et « intérêts d’ordre juridique » me pose trois pro-
                 blèmes : ces expressions ou concepts sont sortis de leur contexte ; la défini-
                 tion que donne la Cour des seconds est problématique ; et, pour autant
                 qu’elle existe, la distinction semble dénuée d’utilité pratique.

                                                                   (Signé) Kenneth Keith.

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