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Summary Contents
Literature international law...................................................................................................2
2.4 – Custom as a source of international law................................................................2
The objective element – state practice.............................................................................3
The subjective requirement – opinio juris.........................................................................3
The relationship between custom and treaty law..............................................................3
3.9 – Interpretation............................................................................................................. 4
4.2.5 – The right to self-determination.............................................................................5
4.2.7 – State Succession...................................................................................................6
7 – State responsibility......................................................................................................6
Attribution of conduct.......................................................................................................7
Responsibility in relation to other states...........................................................................9
Circumstances precluding wrongfulness........................................................................10
12 – The peaceful settlement of dispute........................................................................11
Non-adjudicatory means of settling international disputes..............................................12
Arbitration....................................................................................................................... 13
The international Court of Justice...................................................................................13
International courts and tribunals with a specialized mandate........................................16
13 – The international regulation of the use of force....................................................17
The unilateral use of force by states...............................................................................18
A plea of necessity?.......................................................................................................20
Contentious use of force................................................................................................20
Literature European Law....................................................................................................21
1 – Union Institutions......................................................................................................21
The European Parliament..............................................................................................21
The Council of Ministers.................................................................................................23
The Commission............................................................................................................26
The Court of Justice of the European Union...................................................................27
2 – Union legislation........................................................................................................28
The ordinary legislative procedure.................................................................................28
The ‘special’ legislative procedure..................................................................................30
The principle of subsidiarity............................................................................................30
3 – Union Competences..................................................................................................32
Categories of Union Competences.................................................................................33
5 – Direct effect................................................................................................................ 34
Direct Applicability and Direct Effect...............................................................................35
Direct Effect of Primary Law...........................................................................................35
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Direct Effect of Secondary Law: Directives.....................................................................35
Indirect Effect through National and European law........................................................38
7.3 – Preliminary Rulings I: General aspects.................................................................40
7.4 – Preliminary Rulings II: Special Aspects................................................................42
Weblectures – International Law........................................................................................44
1 – Subjects and Actors..................................................................................................45
1 – Introduction and history............................................................................................45
2 – States....................................................................................................................... 45
3 – Individuals and International organisations...............................................................47
4 – jurisdiction................................................................................................................48
2 – sources....................................................................................................................... 48
1 – Customary international law.....................................................................................48
2 – Unilateral Statements and Soft law..........................................................................49
3 – Treaty law................................................................................................................49
3 – Consequences...........................................................................................................51
1 – Use of Force.............................................................................................................51
4 – Dispute Settlement....................................................................................................51
Weblectures – EU law.........................................................................................................54
1 – Subjects and Actors..................................................................................................54
2 – Sources...................................................................................................................... 55
3 – Consequences...........................................................................................................56
4 – dispute Settlement.....................................................................................................56
Law Cases International law...............................................................................................57
The S.S. Lotus..................................................................................................................57
North Sea Continental Shelf...........................................................................................57
Nicaragua......................................................................................................................... 59
Legality of the Threat or Use of Nuclear Weapons.......................................................60
Law Cases EU law...............................................................................................................60
Declaration of independence in respect of Kosovo......................................................60
ERTA................................................................................................................................. 61
Tobacco Advertising.......................................................................................................62
Literature international law
2.4 – Custom as a source of international law
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To some extent, all law begins with custom. Customary law is based on everyday
interaction of states and therefore has the ability to adapt to changing circumstances.
International customary law arises when a particular way of behaving is:
1. followed as a general among states (objective element)
2. accepted by those states as legally binding (subjective element)
The objective element – state practice
Before a specific pattern of state behaviour becomes legally binding, it must be ‘the way
things are done’. In most cases, this requires consistent repetition of a particular
behaviour, meaning that for a considerable period of time states must have acted in a
certain (identical) manner when confronted with the same facts. In theory, all state acts may
be taken into consideration, but verbal acts must be public, and internal documents and
memoranda do not qualify as state documents.
Conceptually, state practice can be divided into three elements:
1. Consistency requires that practice is reasonably uniform. As long as the conduct is
generally consistent with the rule, and inconsistent conduct is by and large treated as
a breach of the rule rather than an indicator of the recognition of a new rule, the
conduct may suffice.
2. As for duration, practice generally involves slowly and gradually over time, often
through years of repeated behaviour. In situations of rapid change, state practice may
be formed in a very short time potentially paving the way for the creation of so-called
‘instant custom’. A good example is the international reaction to the 9/11 attacks.
3. Generality is the question of how widespread participation in the practice must be.
While unanimity is not required, practice should include the majority of states.
The task is therefore not simply to determine how many states participate in a given
practice, but which states. A state may avoid being bound by an emerging customary
rule by persistently objecting to the practice. The law therefore protects a state from
the imposition by a majority of other states of new obligation upon it while
simultaneously allowing that same majority to progressively develop the law without
having to wait for acceptance of it by every state involved.
The persistent objector rule only applies, however, in relation to new and emerging
customary rules. Once a rule has come into existence, it can no longer be objected
to. New states are also bound by existing customary law. Lastly, the persistent
objector rule does not apply to peremptory norms/jus cogens.
The subjective requirement – opinio juris
State practice, however general and representative, only creates a legally binding custom
when it is accepted as law – the so called requirement of opinio juris sive necessitates. The
purpose of the subjective requirement is to differentiate between acts motivated by a desire
to honour a legal obligation and those that are not. According to the International Law
Association, the existence of sufficient general and representative state practice is usually
sufficient to create a binding custom, and evidence of opinio juris is usually only looked for if
there is reason to believe that a particular behaviour stems from non-legal motivations. The
subjective requirement is particularly relevant where circumstances indicate that a given
practice stems from motivations that are unrelated to law.
The subjective element is important when a state acts contrary to an existing customary rule.
The relationship between custom and treaty law
When a treaty codifies customary international law, the parties to the treaty will be bound by
the treaty as well as customary law while non-parties are only bound by the latter. The ICJ
confirmed the potential existence of such ‘parallel obligations’ in Nicaragua, where it stated
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that the use of interstate force is regulated in both the UN Charter as well as in customary
international law and that the two norms retained a separate existence. Treaty-based
obligation may also be identical to obligations in customary international law if the treaty has
a ‘crystallizing’ effect whereby its content develops into customary law.
When a treaty contains elements of both codification of existing customary law and
progressive developments, non-parties are only bound by the former. If, however, state
practice develops along the lines of the progressive parts of the treaty, the latter may also
become binding as customary international law on the states that are not parties to the
treaty.
When the content of a treaty-based and a custom-based obligation are identical, the two
sources will complement and reinforce each other. If the content of the two are not exactly
identical, a potential conflict can often be avoided through interpretation. But if conflicting
content cannot be reconciled, the question arises which of the two sources prevails:
If one of the two norms has a peremptory/jus cogens character, it prevails
A treaty normally prevails over customary law
Lex posterior: that which is later in time prevails
Lex specialis: the more detailed character prevails
3.9 – Interpretation
Most disputes in international law concern interpretation of treaties, and treaty interpretation
is therefore one of the most important skills of any international lawyer. The relevant
principles of treaty interpretation are found in article 31 and 32 of the VCLT, which reflect
customary international law.
The interpreter must consider 3 elements:
1. Text: According to article 31(4) a ‘special meaning’ must be given to a term in a treaty
provision if ‘it is established that the parties so intended’.
2. According to article 31(2), the context includes not only the treaty’s preamble, but
also annexes as well as agreements and instruments made by the parties in
connection with the conclusion of the treaty. Article 33(3) (a) and (b) permits
consideration of agreements and practice established subsequent to the adaption of
the treaty.
3. Object and purpose: Article 31(3)(c) of the VCLT specifies that, together with the
context, treaty interpretation shall take account of ‘any relevant rules of international
law applicable in the relations between the parties’.
Article 32 of the VCLT concerns the status of the preparatory works to a treaty (travaux
préparatoires), such as preliminary drafts of the treaty, records from conferences and
explanatory statements. Such material is explicitly listed as ‘supplementary means of
interpretation’ and is only to be consulted ‘in order to confirm the meaning resulting from the
application of article 31, or to determine the meaning when the interpretation according to
article 31 either leaves the meaning ambiguous or obscure, or will lead to a result which is
manifestly absurd of unreasonable’.
If a treaty is drafted in more than one language, it may give rise to a host of interpretative
issues. According to article 33 of the VCLT, is a ‘treaty has been authenticated in two or
more languages, the text is equally authoritative in each language unless specified or
agreed’.
Although articles 31 – 33 of the VCLT are intended to govern the interpretation of all types of
treaties, how much weight the interpreter assigns to, respectively, the text, context and object
and purpose of a treaty often depends on the character of the treaty.
