Probleem 2 – The use of cluster munition in armed conflict
Leerdoelen:
Leerdoel 1: What is customary international law?
Leerdoel 2: What is the relationship between treaty and custom (or what if a treaty norm collides with a
customary international law rule? What if they coexist?)
Leerdoel 3: How should a treaty be interpreted?
Boek 1: International Law, hoofdstuk 2.4 en 3.9
Leerdoel 1: What is customary international law?
Customary international law: binds all states and arises when the objective and subjective conditions are
fulfilled.
Objective condition: a general practice among states.
There has to be a consistent repetition of a particular behaviour. This means that for a
considerable period of time states have acted in a certain manner when confronted with the same
facts.
Act of a state: three elements:
Consistency: requires that practice is reasonably uniform.
Duration: practice generally evolves slowly and gradually over time, often through years
of repeated behaviour.
Generality: practice should include the majority of states. The practice by states whose
interests are specially affected is particularly relevant.
Subjective condition: the belief that the practice is legally binding. Opinion juris sive necessitatis.
Purpose: differentiate between acts motivated by a desire to honour, a legal obligation and other
acts.
Evidence of the opinion juris is only looked for if there is reason to believe that particular
behaviour stems from non-legal motivations.
There is a distinction(=onderscheiding) between behaviour at a time when a particular rule begins
to be formed and behaviour at a time when it has already been established.
Relevant when a state acts contrary to an existing customary rule.
Exception: not binding when a state persistently(=aanhoudend) objects.
Also binding when a state has not taken part in the formation of the practice.
Don’t need to be universal.
Leerdoel 2: What is the relationship between treaty and custom (or what if a treaty norm collides with a
customary international law rule? What if they coexist?)
When a treaty codifies customary international law, the parties to the treaty are bound by both the treaty
and customary international law, while non parties are only bound by customary international law.
Crystallizing effect: treaty-based obligations are identical to obligations in customary law when the content
of the treaty develops into customary law. They then complement and reinforce each other.
When a treaty contains elements of codification of existing customary law and progressive developments,
non-parties are bound by the former.
When state practices develops along the lines of the progressive parts of the treaty, then it may also
become binding as customary international law on the non-parties.
Leerdoel 3: How should a treaty be interpreted?
When the obligations in a treaty and customary law are not identical, a conflict can be avoided through
interpretation.
When a treaty is a deliberate(=beraadslagen) act of law-creation, it normally prevails(=heerst) over the
custom between the parties to the treaty.
Lex posterior: which is later in time prevails.
Lex specialis: when there is a conflict between a norm of a general and one of a more detailed
character.
Leerdoelen:
Leerdoel 1: What is customary international law?
Leerdoel 2: What is the relationship between treaty and custom (or what if a treaty norm collides with a
customary international law rule? What if they coexist?)
Leerdoel 3: How should a treaty be interpreted?
Boek 1: International Law, hoofdstuk 2.4 en 3.9
Leerdoel 1: What is customary international law?
Customary international law: binds all states and arises when the objective and subjective conditions are
fulfilled.
Objective condition: a general practice among states.
There has to be a consistent repetition of a particular behaviour. This means that for a
considerable period of time states have acted in a certain manner when confronted with the same
facts.
Act of a state: three elements:
Consistency: requires that practice is reasonably uniform.
Duration: practice generally evolves slowly and gradually over time, often through years
of repeated behaviour.
Generality: practice should include the majority of states. The practice by states whose
interests are specially affected is particularly relevant.
Subjective condition: the belief that the practice is legally binding. Opinion juris sive necessitatis.
Purpose: differentiate between acts motivated by a desire to honour, a legal obligation and other
acts.
Evidence of the opinion juris is only looked for if there is reason to believe that particular
behaviour stems from non-legal motivations.
There is a distinction(=onderscheiding) between behaviour at a time when a particular rule begins
to be formed and behaviour at a time when it has already been established.
Relevant when a state acts contrary to an existing customary rule.
Exception: not binding when a state persistently(=aanhoudend) objects.
Also binding when a state has not taken part in the formation of the practice.
Don’t need to be universal.
Leerdoel 2: What is the relationship between treaty and custom (or what if a treaty norm collides with a
customary international law rule? What if they coexist?)
When a treaty codifies customary international law, the parties to the treaty are bound by both the treaty
and customary international law, while non parties are only bound by customary international law.
Crystallizing effect: treaty-based obligations are identical to obligations in customary law when the content
of the treaty develops into customary law. They then complement and reinforce each other.
When a treaty contains elements of codification of existing customary law and progressive developments,
non-parties are bound by the former.
When state practices develops along the lines of the progressive parts of the treaty, then it may also
become binding as customary international law on the non-parties.
Leerdoel 3: How should a treaty be interpreted?
When the obligations in a treaty and customary law are not identical, a conflict can be avoided through
interpretation.
When a treaty is a deliberate(=beraadslagen) act of law-creation, it normally prevails(=heerst) over the
custom between the parties to the treaty.
Lex posterior: which is later in time prevails.
Lex specialis: when there is a conflict between a norm of a general and one of a more detailed
character.
