CASE LAW PIL
ICJ 1950 ASYLUM CASE (COLOMBIA / PERU)
FACTS: Colombia had granted asylum to a leader of a military rebellion in Peru and qualified him as a political
refugee and requested safe passage for him through Peru. Colombia alleged to be competent itself to qualify the
nature of the offence as a unilateral and binding decision on Peru, based on rule resulting from the 1928
Convention for Asylum and partly on (alleged) custom. In particular, Colombia relied on regional custom peculiar
to Latin-American States.
LAW:
- Regional and local custom: Party must prove that custom is established in a manner binding on other Party.
Party must prove that rule invoked is in accordance with a constant and uniform usage practiced by States in
question and that the usage is an expression of a right to State granting asylum and duty on territorial State.
This follows from art 38 ICJ Statute: “evidence of a general practice accepted as law” (p. 276-277).
- Persistent objector doctrine applied: Even is custom had been proven, this could not be held against Peru,
which rather than displaying an attitude of adherence, has repudiated by not ratifying the Convention (p. 277-
278).
CONCLUSION COURT: Colombia had no competence to unilaterally qualify the offence and bind Peru.
MEMO: -
- Persistent objector doctrine could moreover be found applied in ICJ 1951 ANGLO-NORWEGIAN
FISHERIES: Norway claimed a special delimitation regime on its coastline which the ICJ concurred with as
Norway had always measured its coastline following this regime. ICJ: “even if a general rule had existed at
the time, it would appear inapplicable as against Norway inasmuch as she has always opposed any attempt to
apply it to the Norwegian coast.”
ICJ 1969 NORTH SEA CONTINENTAL SHELF (FED REP GERMANY / DENMARK FED REP
GERMANY / THE NETHERLANDS)
FACTS: A dispute had arisen between the Fed Rep of Germany and Denmark and the Netherlands concerning
the delimitation of the continental shelf between the States. The origin of this dispute lay in the fact that the Fed
Rep Germany’s coast lay in a concave area, which meant that the different methods would lead to a major
difference in area allocated to each State. For this reason, Fed Rep Germany had suggested to delimit the
continental shelf through the principle of a just & equitable share (ex aequo ex bono). Denmark and the
Netherlands on the other hand referred to the equidistance principle, meaning that boundaries are determined by
every point of the shelf which lies closer to the coast of the State than to another coast. The question parties thus
submitted to the ICJ is: What principles and rules of international law are applicable to the delimitation of the
areas of the North Sea? Important here was the question whether article 6 of the 1958 Geneva Convention on the
Continental Shelf, which provided for the equidistance principle, was applicable, or whether any norm had
developed in custom.
LAW:
- On the relation between treaty law and customary law a lex specialis character of treaty provisions:
if a treaty provision is applicable and binding on all parties, provisions of the treaty will prevail and take
precedence on rules of a more general character or derived from other source (para. 25).
- On the status of a signatory party to a Convention which has not ratified the treaty: if a State has signed
but not ratified the treaty, it should not be presumed lightly that a State is willing to be bound (para. 28). [Fed
Rep Germany had signed but not ratified the 1958 Geneva Convention, NL & Denmark contended that
Germany was bound due to its conduct since the signing; Court stated moreover that in this position, it could
still be possible that it would submit a reservation to article 6)
- How a custom could be reflected in a treaty: if a treaty exists on the same topic of the custom, it will be
necessary to examine 1) the status of the principle when convention was drawn up (codification), 2) the effect
of the convention on an emerging principle as the treaty provisions were drawn up (crystallization) and 3)
state practice subsequent of convention (emergence of a new custom, norm-creating character of the treaty
provision) (para 60.)
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,- As regarding the norm-creating character of treaty provisions: this should be analysed through reference
to the creation of customary international law. Two conditions must be fulfilled: 1) acts amount to a settled
practice and 2) acts must be carried out in such a way to be evidence of a belief that this practice is rendered
obligatory by the existence of a rule requiring it (a subjective element). States concerned need to feel to
conform to a legal obligation: frequency or habitual character is not enough (para 77).
- The element of time for the formation of custom: even without the passage of considerable amounts of
time, a very widespread and representative participation in a Convention may suffice of itself (para 73 –
regarding the formation of custom in treaty formation). The passage of only a short period of time need not
necessarily be a bar to the formation of custom on basis of purely a conventional rule, but an indispensable
requirement would be that State practice, especially specially affected States, would have been extensive and
virtually uniform and occurred in such a way that general recognition that a rule of law is involved (para 74
– formation of custom after provision is into force).
CONCLUSION COURT: No CIL on equidistance principle, continental shelf has to be divided ex aequo ex bono.
MEMO:
- The decisions of the Court in the North Sea Continental Shelf have been reflected in the ILC Conclusions on
the Formation of Custom para 60. 3 options of assessing whether CIL is reflected in a treaty (codification,
crystallization, norm creation) = Conclusion 11(a-c).
- On the sequence of custom formation following a treaty: settled practice must come first, then confirmed by
opinio juris (para 77). The implications of this approach are that it is essential to find evidence of an opinio
juris not to be assumed lightly. Compare to 1986 ICJ Nicaragua para 184: a shared view of States (opinio
juris) must be confirmed by practice. Difference between Nicaragua and NSCS in this regard: in Nicaragua
there was a consensus on the agreement of a legal obligation, while in NSCS the question was what the legal
obligation was.
- Comparing North Sea Continental Shelf and Nicaragua: NSCS is about the development of custom following
a treaty, N is about distinguishing between rules of treaty law and rules of CIL
ICJ 1984 AO DELIMITATION OF THE MARITIME BOUNDARY IN GULF OF MAINE (CANADA /
UNITED STATES)
FACTS: Canada and the US requested the Court to answer the question of the course of the single maritime
boundary that divides the continental shelf and fisheries zone of the two parties in the Gulf of Maine area in line
with the rules and principles of international law.
LAW:
- On customary law and treaty law: CIL can of its nature only logically refer to a few basic legal principles,
which lay down guidelines to be followed with a view to an essential question (para 81). The same cannot be
said for international treaty law: nothing prevents the parties to a convention (bi- and multilateral) from
extending the rules contained in that convention to aspects which is less likely that CIL would govern (para
82). [MEMO: i.e. introduce technicalities and methods]. It is in codifying [general] conventions that principles
and rules of general application can be identified. Such conventions must, moreover, be seen against the
background of CIL and interpreted in its light (para 83). General CIL is therefore not the proper place in which
to seek specific rules or methods [for a delimitation] but merely contains a general requirement [of the
application of equitable criteria and utilisation of practical methods] (para 114).
- On the nature of customary international law, opinio juris and State practice: A body of detailed rules is
not to be looked for in CIL which in fact comprises a limited set of norms for ensuring the co-existence and
vital co-operation of the members of the international community, together with a set of customary rules
whose presence in the opinio juris of States can be tested by induction based on the analysis of a sufficiently
extensive and convincing practice, and not by deduction from preconceived ideas (para 111).
- Tacit acquiescence as acceptance of custom: tacit unilateral acceptance of a customary norm is a form of
consent (para 130).
CONCLUSION COURT: while Canada and the US disagreed on the rules of international law to be applied,
which both were based on preconceived ideas, both agreed on the fundamental norm governing the delimitation:
equitable result and the use of practical methods to ensure an equitable result (negotiations).
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,MEMO: One of the two cases in which the Court appointed an expert (the other is the 1949 Corfu Channel).
ICJ 1996 AO LEGALITY OF THE THREAT OR USE OF NUCLEAR WEAPONS
FACTS: The General Assembly requested an AO on the question: Is the threat or use of nuclear weapons in any
circumstance permitted under international law? The Court turned to the law related to the use of force and the
law applicable in armed conflict as well as any treaties related to nuclear weapons to answer this question (para
34). The Court found that there is no international customary law and treaty provision authorizing threat or use
of nuclear weapons or any other weapon in general. Rather, State practice demonstrating a view of illegality of
certain weapons generally resorts to a prohibition (para 52.). The Court therefore set out to find a prohibition,
which it sought to find in CIL as no treaty exists on the topic.
LAW:
- As to the opinio juris on the prohibition of nuclear weapons: some States pointed to the non-use of nuclear
weapons since 1945 as an expression of opinio juris to the prohibition of nuclear weapons, while other States
pointed to a policy of deterrence and a claim to self-defence; non-utilisation of nuclear weapons rather
explained as no opportunity has arisen for employment. Court cannot find an opinio juris due to this division.
- The role of General Assembly resolutions: if a GA resolution provides evidence important for the
establishment of the existence of (an emergence) of an opinio juris, it will be necessary to look at its content
and the conditions of its adoption, whether an opinio juris exists as to its normative character (para 70.)
- The relationship of nuclear weapons to the prohibition of the use of force: the question of the legality of
the use of nuclear weapons must be determined in recourse to the use of force in UN Ch (para 37). The UN
Ch neither prohibits nor permits particular types of weapons (para 39). It must therefore be assessed in light
of self-defence (art 51 UN Ch) – governed by necessity and proportionality; this dual condition applies equally
to the UN Ch (para 41). The proportionality principle does not in itself exclude nuclear weapons, however
proportionate force under self-defence must also meet proportionality under IHL (para 42).
- More particular the relation of policy of deterrence to the prohibition of use of force: whether a signalled
intention to use force in occurrence of certain events will form a “threat” in the sense of art 2(4) UN Ch is
dependent on the lawfulness of the envisaged method. If its unlawful, it will be prohibited under 2(4). If the
use of force is illegal, the threat of that use of force will be illegal (para 47). Whether the policy of deterrence
is thus a threat contrary to 2(4) is dependent on whether it would be against the territorial integrity or political
independence of target State, against the Purposes of the UN or necessarily violate necessity & proportionality
(para 48).
- On the protection of the environment and its definition: States must respect the environment of other
States (para 29). The environment is defined as representing the living space, quality of life and health of
human beings, including generations unborn (para 29) [anthropocentric definition clarifying dependence on
environment].
CONCLUSION COURT: the use of nuclear weapons needs to meet the requirements of article 51 UN Ch and
principle of IHL. Generally speaking, the threat of use of nuclear weapons would be counter to general principles
of IHL, but the question of lawfulness cannot be answered in relation to the differing positions of States regarding
the non-use of nuclear weapons / policy of deterrence.
MEMO:
- This AO is an example of a case where inaction just indicated a lack of action instead of the inaction
demonstrating a State practice (policy of deterrence). Example then of a case were inaction did signal State
practice: ICJ 2009 DISPUTE REGARDING NAVIGATIONAL AND RELATED RIGHTS (COSTA
RICA/NICARAGUA) concerned fishing in the EEZ (para 141): “failure of Nicaragua to deny (…)
[practice in question] which had continued undisturbed and unquestioned over a very long period of time (…)
conclusion Costa Rica had customary right.”
- Compare to ICJ 1986 Nicaragua para 188 for role of General Assembly resolutions. Also compare to ICJ AO
Chagos for the application of these rules.
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, ICJ 1986 MILITARY AND PARAMILITY ACTIVITIES IN AND AGAINST NICARAGUA
(NICARAGUA V. UNITED STATES)
FACTS: Nicaragua filed proceedings against the US, asking the Court to declare that the USA by supporting
military and paramilitary groups (contras) in Nicaragua had violated article 2(4) of the UN Ch and also that it had
violated the sovereignty of Nicaragua and is using force in Nicaragua. The US countered that the Court had no
jurisdiction and stated to have relied on a collective self-defence based on article 51 UN Ch. Nicaragua argued
that the US had control over the contras and that the US also had executed several military actions against
Nicaragua itself (attacks on ports and oil installations).
LAW:
- The coexistence of customary law and treaty law: the US argued that since article 2(4) codified the law on
the use of force, the UN Ch had “subsumed” the law on the use of force and therefore this law no longer
existed independently as CIL. The Court disagreed: the codification of CIL does not mean that the customary
norms cease to exist (para 174). Even if the treaty norm and the customary norm have exactly the same content,
the customary norm would not be deprived of separate applicability (para 175). Reference to the North Sea
Continental Shelf case (para 63): the coexistence of custom and treaty recognized through mentioned
processes of codification, crystallization or emergence of norm in relationship (para 177). Treaty law and
customary law should be kept separately for two reasons: (1) the material breach of a treaty norm would
justify the other party to breach its obligations under treaty law, but bound by CIL the injured party would
remain bound (2) a treaty may specify modalities and mechanisms for implementation (para 178).
- On customary law: where there is opinio juris, it must be confirmed by State practice. Thus, if two States
agree to incorporate a particular rule in a treaty, this agreement would suffice to make the rule binding on
them; but with regards to CIL, the shared view of parties on the content of what they regard as custom is
insufficient: there must also be practice (para 184). For a rule to be established as customary, the
corresponding practice does not necessarily have to be in rigorous conformity. The conduct of States should
generally be consistent with such rules and instances of inconsistent conduct be considered as breaches of the
rule. Also, if a State defends it conduct by appealing to exceptions or justifications, the significance of the
attitude is to confirm rule rather than reject it (para 186).
- Customary law – does deviation from State practice indicate a new custom? Reliance by a State on a
novel right or an unprecedented exception to the principle might, if shared in principle by other States, tend
towards a modification of CIL. Conduct prima facie inconsistent with a custom depends thus significantly on
the justification offered whether it indicates a new custom (para 207 – see also para 186). [I.c. the Court rejects
the emergence of a new custom of foreign intervention for the benefit of opposition forces or decolonization.]
- On the possibility of deducing opinio juris from General Assembly resolutions: opinio juris may be
deduced – with caution – from the attitude of Parties and the attitudes of State towards GA resolutions (para
188 – discussed in context of reso 2625 (XXV) 1970 Declaration on Friendly Relations; signing this resolution
may be understood as an acceptance of the validity of the rule in the resolution through its reiteration of the
UN Ch).
- Customary status of the principle of non-use of force: principle of non-use of force may be regarded as a
principle of CIL (para 174, 188).
- Customary status of the principle of non-intervention: the principle of non-intervention involves the right
of every sovereign State to conduct its affairs without outside interference. It is part and parcel of CIL (para
202). Its content: the prohibition to intervene directly or indirectly in the internal or external affairs of other
States; including the choice of a political, economic, social and cultural system and the formulation of a
foreign policy (para 205).
- Also recognized as customary: the non-use of force, non-intervention, respect for the independence and
territorial integrity of States, freedom of navigation (para 174).
- Whether the US could be attributed responsibility for the conduct of the paramilitary groups: The
degree of control of a State over a group is relevant for claims to attribute responsibility of a State to the
actions of the group. For the conduct of (para)military groups to give rise to legal responsibility of a State, it
would in principle have to be proven that that State had effective control over the operations of the group
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