International law summary
Week 1
Article 38 of the ICJ: gives all sources of international law.
There is no hierarchy in international law, but there is a frequently used order in practice.
Some examples are treaties, principles of the law and custom
Treaties: it is a binding agreement between two or more states. We can nd this in the Vienna
Convention (VCLT). Treaties are written down. It may for example re ect customary law, which is
codi ed
Custom: it consists of state practice and opinio juris. The state practice must be uniform and
consistent. There are no rules under duration of custom.
Principles of the law: they often come from domestic legal systems.
When do we speak of an state? (article 1 Montevideo Convention)
1. Does it have population?
2. Does it have a government?
→ de facto
→ de jure
3. Does it have territory?
4. Is it recognized as a state?
→ declaratory theory
→ constitutive theory
Customary law (custom): a state has to do practice, has to be uniform and wide spread and
representative
- Opinio juris: legal opinion, someone can agree, be neutral or disagree (accept, silent,
object)
- Codi cation: it must be written down like a treaty
- Jus cogens: mandatory law, something that is forbidden in the whole world. All states are
tied to these rules. Example: genocide, slavery, torture, piracy, human tra cking
Legal personality: gives rights, duties and obligations to states within international legal system
States ‘have’ such personality. International organisations too, but not all.
- Erga omnes obligations embedded this concept: an obligation between 2 or more states
- Hard law: binding, written down.
- Soft law: non-binding, but signi cant for change, it’s more like a guideline.
Een treaty is niet exibeler dan een custom, een treaty is geschreven terwijl een custom niet
geschreven is.
Treaty vs Custom
- Exists simultaneously
→Pre-1960 it was all custom
- UN Commission drafted the VCLT, thus codifying treaty-related custom
- VCLT focusses on common understanding and process of treaty-creation
- Domestic law (binnenlands) regulates implementation of int. Treaties
- Monism vs. dualism
1
fifi fl fi fl fi ffi
, → Monism: internationaal en nationaal recht is één rechtssysteem
→ dualism: internationaal en nationaal recht zijn afzonderlijke rechtssystemen.
International Playground
- Who plays around?
States, UN, EU, international courts and tribunals
- How is this “playground” established? Are there rules?
Customs and codi cation thereof. It had to start somewhere!
“If you make it, then don’t break it!”
- Treaty interpretation is key to abide by the rules of the int. community;
- Soft law = non-binding, but signi cant for change nonetheles
- UN General Assembly Resolutions provide for guidelines, directions, standard
- International documents on e.g. commercial sheries, factory standards, self-
determination etc. provide for support in the creation and maintainence of int.
All sources of law:
1. Treaties: binding international agreement
2. Customary law: unwritten rule. Exists of state practice and opinio juris
3. Judicial decisions
4. Juristic writings
5. General principles of law
2
fi fi fi
, Week 2
Treaty article 2 of the VCLT: an international agreement concluded between states in written form
and governed by international law, whether embodied in a single instrument or in two or more
related instruments and whatever its particular designation.
- We need treaties because they make life easier. There is less interpretation
Reservations: we like the treaty, but not every article of it. Unilateral statement where states
express to exclude or modify the legal e ect of certain provisions of the treaty in their application
to the state. Reservations are allowed, because we want as many states as possible to
participate.
Custom reservation: Reservations (voorbehoud) must be accepted (implicit/by VCLT) given that:
- They are within scope; valt binnen het bereik
- Contractually acceptable; contractueel mogelijk
- They do not defeat the object and purpose of the treaty; niet ondermijnen van doel van
verdrag.
• Reserving State; Making the reservation(s)
• Objecting State; Objecting to reservation(s), thus creating challenges!
Treaty reservation:
art. 2 VCLT → A declaration by a state made upon signing or ratifying a treaty that the state
reserves the right not to abide by certain provisions of the treaty
Purposes of a reservation.
1. To exclude a particular provision.
2. To modify the legal e ect of a provision according to a State’s own interpretation.
3. To interpret the meaning or extent its attribution to a given treaty or provisions
Three situations when it is not allowed (see art. 19 VCT);
Enables a State to participate in a treaty without being ‘forced’ to accept all provisions;
Reservations may also be withdrawn (see arts. 22, 23(4) VCLT).
Implementation and interpretation
- there are so-called ‘layered’ treaties
Annexes, amendments, protocols
E.g., Geneva Additional Protocols
- General principle: Lex Posterior Derogat Lex Priori
- Pacta Sunt Servanda (art. 26 VCLT)
Is applicable after entry into force!
And equally signi cant is art. 31(1) VCLT
- Ordinary interpretation is the standard method, but there are more
- Structure is key when drafting a treaty
International treaties more or less have the same structure
Pacta sunt servanda: article 26 of the VCLT
Treaty enters into force article 31 of the VCLT
3
fi ff ff
Week 1
Article 38 of the ICJ: gives all sources of international law.
There is no hierarchy in international law, but there is a frequently used order in practice.
Some examples are treaties, principles of the law and custom
Treaties: it is a binding agreement between two or more states. We can nd this in the Vienna
Convention (VCLT). Treaties are written down. It may for example re ect customary law, which is
codi ed
Custom: it consists of state practice and opinio juris. The state practice must be uniform and
consistent. There are no rules under duration of custom.
Principles of the law: they often come from domestic legal systems.
When do we speak of an state? (article 1 Montevideo Convention)
1. Does it have population?
2. Does it have a government?
→ de facto
→ de jure
3. Does it have territory?
4. Is it recognized as a state?
→ declaratory theory
→ constitutive theory
Customary law (custom): a state has to do practice, has to be uniform and wide spread and
representative
- Opinio juris: legal opinion, someone can agree, be neutral or disagree (accept, silent,
object)
- Codi cation: it must be written down like a treaty
- Jus cogens: mandatory law, something that is forbidden in the whole world. All states are
tied to these rules. Example: genocide, slavery, torture, piracy, human tra cking
Legal personality: gives rights, duties and obligations to states within international legal system
States ‘have’ such personality. International organisations too, but not all.
- Erga omnes obligations embedded this concept: an obligation between 2 or more states
- Hard law: binding, written down.
- Soft law: non-binding, but signi cant for change, it’s more like a guideline.
Een treaty is niet exibeler dan een custom, een treaty is geschreven terwijl een custom niet
geschreven is.
Treaty vs Custom
- Exists simultaneously
→Pre-1960 it was all custom
- UN Commission drafted the VCLT, thus codifying treaty-related custom
- VCLT focusses on common understanding and process of treaty-creation
- Domestic law (binnenlands) regulates implementation of int. Treaties
- Monism vs. dualism
1
fifi fl fi fl fi ffi
, → Monism: internationaal en nationaal recht is één rechtssysteem
→ dualism: internationaal en nationaal recht zijn afzonderlijke rechtssystemen.
International Playground
- Who plays around?
States, UN, EU, international courts and tribunals
- How is this “playground” established? Are there rules?
Customs and codi cation thereof. It had to start somewhere!
“If you make it, then don’t break it!”
- Treaty interpretation is key to abide by the rules of the int. community;
- Soft law = non-binding, but signi cant for change nonetheles
- UN General Assembly Resolutions provide for guidelines, directions, standard
- International documents on e.g. commercial sheries, factory standards, self-
determination etc. provide for support in the creation and maintainence of int.
All sources of law:
1. Treaties: binding international agreement
2. Customary law: unwritten rule. Exists of state practice and opinio juris
3. Judicial decisions
4. Juristic writings
5. General principles of law
2
fi fi fi
, Week 2
Treaty article 2 of the VCLT: an international agreement concluded between states in written form
and governed by international law, whether embodied in a single instrument or in two or more
related instruments and whatever its particular designation.
- We need treaties because they make life easier. There is less interpretation
Reservations: we like the treaty, but not every article of it. Unilateral statement where states
express to exclude or modify the legal e ect of certain provisions of the treaty in their application
to the state. Reservations are allowed, because we want as many states as possible to
participate.
Custom reservation: Reservations (voorbehoud) must be accepted (implicit/by VCLT) given that:
- They are within scope; valt binnen het bereik
- Contractually acceptable; contractueel mogelijk
- They do not defeat the object and purpose of the treaty; niet ondermijnen van doel van
verdrag.
• Reserving State; Making the reservation(s)
• Objecting State; Objecting to reservation(s), thus creating challenges!
Treaty reservation:
art. 2 VCLT → A declaration by a state made upon signing or ratifying a treaty that the state
reserves the right not to abide by certain provisions of the treaty
Purposes of a reservation.
1. To exclude a particular provision.
2. To modify the legal e ect of a provision according to a State’s own interpretation.
3. To interpret the meaning or extent its attribution to a given treaty or provisions
Three situations when it is not allowed (see art. 19 VCT);
Enables a State to participate in a treaty without being ‘forced’ to accept all provisions;
Reservations may also be withdrawn (see arts. 22, 23(4) VCLT).
Implementation and interpretation
- there are so-called ‘layered’ treaties
Annexes, amendments, protocols
E.g., Geneva Additional Protocols
- General principle: Lex Posterior Derogat Lex Priori
- Pacta Sunt Servanda (art. 26 VCLT)
Is applicable after entry into force!
And equally signi cant is art. 31(1) VCLT
- Ordinary interpretation is the standard method, but there are more
- Structure is key when drafting a treaty
International treaties more or less have the same structure
Pacta sunt servanda: article 26 of the VCLT
Treaty enters into force article 31 of the VCLT
3
fi ff ff
