Public International Law – Lectures
Lecture 1 - Sources of International law
Article 38 (1) ICJ Statute
-authoritative sources of international law, list of sources
-where international law begins and ends
-argument needs to be based on one of these sources of the article; make analysis of sources
ICJ statute as a source of law
-international convention; treaty
-sets up court and a procedure of international court of justice
-rules for resolving legal dispute
-specifies sources of international law
What are the sources?
a) Treaties or international conventions – legal document between two or more states (“contracts”
treaties)
-bilateral
-multilateral
-universal (UN Charter-193 states are parties; not a party Kosovo (but it is not a state,
complicated) and Vatican)
-Treaties are diverse-use contract law logic when you have treaties
b) International custom-NO hierarchy between sources, something has to come first, no list
-2 elements: state practice and opinio juris (north sea con shelf)
-state practice: how state act, behave
-opinio juris: psychological element, state don’t engage in certain behaviour just like that but
because they believe international law requires them to do that, not just practice, belief of state
included
-to have some custom we need opinio juris and belief of state-what was first opinio or custom?
Custom, but to have this you need opinio juris (interconnected)
-we don’t need an answer what was first-custom develops during time, and at some point, we
can say that rule turned into some rule of international law, but not specific date
-when 25th state ratifies then we have a treaty (usually we need ratification; sometimes only
signature enough; depends on the treaty itself)
-but with custom we can specify when practice started to emerge, and when it became universal,
and at what point it started to be opinio juris, and at some point, at 2018 started to be rule of
international law-only determine certain period but not date with custom or opinio juris
-custom-not numerical answer, but big states play a role, relevance of states or interest for
particular rule (Switzerland and sea example)
c) general principles
-corfu channel-gp are source of law
-gap filling; basic fundamental pillars; inchoate custom...-various definitions
-recognized by (civilized) nations
-law that applies in most countries
-they are not general and are not principles-GP are rules, sources of law, rule consists of
conditions and consequences, rules are contracted by principles, GP no definitive outcome or
consequence
1
, -example: France and Guinea-sovereign equality-rule that arise that principles that make state
equal and sovereign Art 2 (4) Prohibition of Use of Force, no intervention, Nicaragua and Oil
platforms cases (Iran v US), jurisdictional immunity
-Permanent Court of International Justice-problem in application if there is no treaty or custom-
rationale to avoid situation where no rule can be applicable- resolution making new rule
general principles
-Corfu Channel case-no use of territory on detriment of another state-general principles cited as
source of rules
-can be a secondary rule-how rules are made, destroyed, how to change constitution, how court
functions, good faith, duties of reparation...-those all can be general principles
-delete “civilized nations” general principles recognized (by international community)-
everyone are part of international community-companies, BGOs, IGOs, states, international
courts and tribunals...
-domestic law might not translate into international law-but domestic law can be recognised or
considered, but we must make sure that such rule fits into international law
-drawing lines of properties has source in Roman law which is moderated, changed
-law has been decided-res judicata (a matter that has been adjudicated by a competent court and
therefore may not be pursued further by the same parties)
d) subject to the provisions of Article 59 ICJ Statute, judicial decisions, and the teachings of the
most highly qualified publicists of the various nations, as subsidiary means for the determination
of rules of law
-subsidiary means-not a primary source, no same weight as treaties, they are more interpretative
to help us determine legal obligations which tells us rules of customary laws ICJ helped us
clarify such rules
-not binding but important in identifying legal obligations
-2 kinds of subsidiary sources:
1. judicial decisions-no “international” but also domestic relevance that deals with
international law jurisdiction and immunities (in what circumstances can domestic
court apply international law or play important role)-domestic courts play central role as
organs of state which contribute to state practice
2. teachings of the most highly qualified publicists of the various nations (academics)-not
publicist as published but as expert in public int. law (French)
Is there a hierarchy of sources?
-no formal system of precedence of international law like in common law
-previous case law can be important as subsidiary source of law
-Nicaragua case – ICJ said about relation of treaty and custom existence of the convention that
codifies custom does not mean that custom has been extinguished - obligations from treaty and custom
can apply at the same time, parallel-treaty and custom can both be binding on a state
-treaty crystallises or codify sth that has been customary-before Vienna Convention on the Law of
Treaties (VCLT) there was custom and with Vienna Convention it became clear and it codified pre-existing
custom
-treaty can be a source of new custom because some aspects have not been customary before
-we have 190 states party to treaty T but state A is not a party, can we say that state A is legally obliged
to comply with such treaty? No! Only via customary international law, a reflection of the treaty, this does
not mean that state A is a party of the treaty via custom but must comply with rules that are made
according to custom
-concept of persistence (persistent objector)-anglo Norwegian fish case-customary international law is
generally binding on all state, but if state wants to get out of custom law it needs to prove that it
persistently did not comply, it always opposed it, it cannot oppose it later, it needs to prove its
persistency from the very early formal beginning of the custom
2
, definition: a persistent objector is a sovereign state which has consistently and clearly
objected to a norm of customary international law since the norm's emergence, and
considers itself not bound to observe the norm
-reservations in the treaties-state can get out of certain obligations (week 2)-always check reservations in
the treaty and custom law
What is the legal status of:
-UN Security Council’s resolutions? Not all of them are legally binding, those that are not can be
important for opinio juris
legally binding are the ones under Chapter 7 of UN Charter (international peace and
security), they fit under international conventions of the scheme of sources, they are treaty
mechanism
15 states are part of UN Security Council (5 permanent)
-UN General Assembly’s resolutions? Not legally binding, not completely irrelevant, they are
recommendations, customs, state practice in GA all states are presented
it has 192 member-states
Nicaragua case para 188-GA resolutions can be seen as state practice and potentially opinio
juris but only when adopted unanimously or nearly unanimously)
Legality of the threat of the use of weapons case
-Jus cogens-invalidates treaties if they are against or breaching jus cogens
Art 53 VCLT
Germany v Italy-icj: yes jus cogens but not here
-good example of public law in terms of contract
-do not overuse this concept!!
*States reservation under the treaty is not reflected in the custom, reservation can be good evidence of
persistent rejection, but not enough, still must object from the beginning
Lecture 2 – The Law of Treaties (VCLT)
Content
-concept and applicable law
-formation and entry into force
-structure
-reservations-modifying states relationship and obligations
-application/interpretation
-invalidity
-termination/suspension/withdrawal
Concept and applicable law
-contracts between states?
Treaties different from contracts-some things applicable to treaties from contracts, but not solely
contractual in nature
Westphalian system-based on sovereignty and consent of states
Bilateral relations
Pacta sunt servanda
-applicable law
secondary rules-rules about other rules, no direct first primary rule
3
, “do not use force” is primary-secondary is can we terminate UN Charter and similar
VCLT 1969/1986 (only applies to treaties between states)-read all rules!!!!
-termination and suspensions and similar
-number of parties: 160
does not apply to India, US, France
-customary international law
-General principles-lots of main rules are general principles like pacta sunt servanda
-careful with rules that you apply
-both states need to be parties to apply VCLT
-limitation on application of VCLT: Art 4 (non-retroactivity clause) and to parties and their earlier
treaties
-1980s entered into force
-VCLT does not apply to UN Charter
-a lot of VCLT rules are custom, but not all
-treaty- Art 2 (1)(a) VCLT 1969
international agreement, between states, written form, governed by international law
“governed by international law“ meaningparties intend to create something that is governed
by international law and binding on them
not governed by international law-political influence and statement, memorandum of
understanding, not binding, Helsinki Final Act...
preamble and formulation-says that sth is binding or not; intentions of parties mentioned...
-Qatar v Bahrain (jurisdictions) 1994 ICJ Rep 112-exchange of letter by heads of states, does not look like
treaty, but fulfilled its criteria
-Cameroon v Nigeria, 2002 ICJ Rep 303-fulfilled criteria-amounted to treaty for the purposes of
international law
-agreements between states and other entities? EU and Belgium agreement on properties, ICC
agreements on property in Hague where court is located
IO treaties-Canada and EU agreement, WTO agreement, NATO
Art 3 VCLT 1969
sth that is not governed by VCLT treaty doesn’t mean it is not a treaty
-states and agreements with non-states and other organisations like private companies
Anglo Iranian Oil 1952 ICJ rep 93
Texaco v Libya case, 1977-even in these situations parties can take international rules as general
law
Treaty rules in strictu sensu are not applicable to these agreement bc they are not treaties but as
general rule can be applicable
Peace agreements? CA 3 Geneva Conventions 1949-Syria agreement, Columbia peace
agreement, liberation armies-non-state actors-what’s the legal status of these and are they
governed by treaty law? No concrete answer yet on this-but, agreements allow further
application of international law
Formation and entry into force
-Treaties are result of political process, states decide for a treaty to create it, VCLT was product of ILC
(International Law Commission)
-Authority to conclude treaties: states, who can sign?
-Art 7 VCLT 1969-authority to conclude treaties-heads of states, heads of governments...
-heads of state-president, queen
-heads of governments-prime minister, everyone with executive functions, depends on the
system
-president can expressly give powers to some head of ministry...
4
Lecture 1 - Sources of International law
Article 38 (1) ICJ Statute
-authoritative sources of international law, list of sources
-where international law begins and ends
-argument needs to be based on one of these sources of the article; make analysis of sources
ICJ statute as a source of law
-international convention; treaty
-sets up court and a procedure of international court of justice
-rules for resolving legal dispute
-specifies sources of international law
What are the sources?
a) Treaties or international conventions – legal document between two or more states (“contracts”
treaties)
-bilateral
-multilateral
-universal (UN Charter-193 states are parties; not a party Kosovo (but it is not a state,
complicated) and Vatican)
-Treaties are diverse-use contract law logic when you have treaties
b) International custom-NO hierarchy between sources, something has to come first, no list
-2 elements: state practice and opinio juris (north sea con shelf)
-state practice: how state act, behave
-opinio juris: psychological element, state don’t engage in certain behaviour just like that but
because they believe international law requires them to do that, not just practice, belief of state
included
-to have some custom we need opinio juris and belief of state-what was first opinio or custom?
Custom, but to have this you need opinio juris (interconnected)
-we don’t need an answer what was first-custom develops during time, and at some point, we
can say that rule turned into some rule of international law, but not specific date
-when 25th state ratifies then we have a treaty (usually we need ratification; sometimes only
signature enough; depends on the treaty itself)
-but with custom we can specify when practice started to emerge, and when it became universal,
and at what point it started to be opinio juris, and at some point, at 2018 started to be rule of
international law-only determine certain period but not date with custom or opinio juris
-custom-not numerical answer, but big states play a role, relevance of states or interest for
particular rule (Switzerland and sea example)
c) general principles
-corfu channel-gp are source of law
-gap filling; basic fundamental pillars; inchoate custom...-various definitions
-recognized by (civilized) nations
-law that applies in most countries
-they are not general and are not principles-GP are rules, sources of law, rule consists of
conditions and consequences, rules are contracted by principles, GP no definitive outcome or
consequence
1
, -example: France and Guinea-sovereign equality-rule that arise that principles that make state
equal and sovereign Art 2 (4) Prohibition of Use of Force, no intervention, Nicaragua and Oil
platforms cases (Iran v US), jurisdictional immunity
-Permanent Court of International Justice-problem in application if there is no treaty or custom-
rationale to avoid situation where no rule can be applicable- resolution making new rule
general principles
-Corfu Channel case-no use of territory on detriment of another state-general principles cited as
source of rules
-can be a secondary rule-how rules are made, destroyed, how to change constitution, how court
functions, good faith, duties of reparation...-those all can be general principles
-delete “civilized nations” general principles recognized (by international community)-
everyone are part of international community-companies, BGOs, IGOs, states, international
courts and tribunals...
-domestic law might not translate into international law-but domestic law can be recognised or
considered, but we must make sure that such rule fits into international law
-drawing lines of properties has source in Roman law which is moderated, changed
-law has been decided-res judicata (a matter that has been adjudicated by a competent court and
therefore may not be pursued further by the same parties)
d) subject to the provisions of Article 59 ICJ Statute, judicial decisions, and the teachings of the
most highly qualified publicists of the various nations, as subsidiary means for the determination
of rules of law
-subsidiary means-not a primary source, no same weight as treaties, they are more interpretative
to help us determine legal obligations which tells us rules of customary laws ICJ helped us
clarify such rules
-not binding but important in identifying legal obligations
-2 kinds of subsidiary sources:
1. judicial decisions-no “international” but also domestic relevance that deals with
international law jurisdiction and immunities (in what circumstances can domestic
court apply international law or play important role)-domestic courts play central role as
organs of state which contribute to state practice
2. teachings of the most highly qualified publicists of the various nations (academics)-not
publicist as published but as expert in public int. law (French)
Is there a hierarchy of sources?
-no formal system of precedence of international law like in common law
-previous case law can be important as subsidiary source of law
-Nicaragua case – ICJ said about relation of treaty and custom existence of the convention that
codifies custom does not mean that custom has been extinguished - obligations from treaty and custom
can apply at the same time, parallel-treaty and custom can both be binding on a state
-treaty crystallises or codify sth that has been customary-before Vienna Convention on the Law of
Treaties (VCLT) there was custom and with Vienna Convention it became clear and it codified pre-existing
custom
-treaty can be a source of new custom because some aspects have not been customary before
-we have 190 states party to treaty T but state A is not a party, can we say that state A is legally obliged
to comply with such treaty? No! Only via customary international law, a reflection of the treaty, this does
not mean that state A is a party of the treaty via custom but must comply with rules that are made
according to custom
-concept of persistence (persistent objector)-anglo Norwegian fish case-customary international law is
generally binding on all state, but if state wants to get out of custom law it needs to prove that it
persistently did not comply, it always opposed it, it cannot oppose it later, it needs to prove its
persistency from the very early formal beginning of the custom
2
, definition: a persistent objector is a sovereign state which has consistently and clearly
objected to a norm of customary international law since the norm's emergence, and
considers itself not bound to observe the norm
-reservations in the treaties-state can get out of certain obligations (week 2)-always check reservations in
the treaty and custom law
What is the legal status of:
-UN Security Council’s resolutions? Not all of them are legally binding, those that are not can be
important for opinio juris
legally binding are the ones under Chapter 7 of UN Charter (international peace and
security), they fit under international conventions of the scheme of sources, they are treaty
mechanism
15 states are part of UN Security Council (5 permanent)
-UN General Assembly’s resolutions? Not legally binding, not completely irrelevant, they are
recommendations, customs, state practice in GA all states are presented
it has 192 member-states
Nicaragua case para 188-GA resolutions can be seen as state practice and potentially opinio
juris but only when adopted unanimously or nearly unanimously)
Legality of the threat of the use of weapons case
-Jus cogens-invalidates treaties if they are against or breaching jus cogens
Art 53 VCLT
Germany v Italy-icj: yes jus cogens but not here
-good example of public law in terms of contract
-do not overuse this concept!!
*States reservation under the treaty is not reflected in the custom, reservation can be good evidence of
persistent rejection, but not enough, still must object from the beginning
Lecture 2 – The Law of Treaties (VCLT)
Content
-concept and applicable law
-formation and entry into force
-structure
-reservations-modifying states relationship and obligations
-application/interpretation
-invalidity
-termination/suspension/withdrawal
Concept and applicable law
-contracts between states?
Treaties different from contracts-some things applicable to treaties from contracts, but not solely
contractual in nature
Westphalian system-based on sovereignty and consent of states
Bilateral relations
Pacta sunt servanda
-applicable law
secondary rules-rules about other rules, no direct first primary rule
3
, “do not use force” is primary-secondary is can we terminate UN Charter and similar
VCLT 1969/1986 (only applies to treaties between states)-read all rules!!!!
-termination and suspensions and similar
-number of parties: 160
does not apply to India, US, France
-customary international law
-General principles-lots of main rules are general principles like pacta sunt servanda
-careful with rules that you apply
-both states need to be parties to apply VCLT
-limitation on application of VCLT: Art 4 (non-retroactivity clause) and to parties and their earlier
treaties
-1980s entered into force
-VCLT does not apply to UN Charter
-a lot of VCLT rules are custom, but not all
-treaty- Art 2 (1)(a) VCLT 1969
international agreement, between states, written form, governed by international law
“governed by international law“ meaningparties intend to create something that is governed
by international law and binding on them
not governed by international law-political influence and statement, memorandum of
understanding, not binding, Helsinki Final Act...
preamble and formulation-says that sth is binding or not; intentions of parties mentioned...
-Qatar v Bahrain (jurisdictions) 1994 ICJ Rep 112-exchange of letter by heads of states, does not look like
treaty, but fulfilled its criteria
-Cameroon v Nigeria, 2002 ICJ Rep 303-fulfilled criteria-amounted to treaty for the purposes of
international law
-agreements between states and other entities? EU and Belgium agreement on properties, ICC
agreements on property in Hague where court is located
IO treaties-Canada and EU agreement, WTO agreement, NATO
Art 3 VCLT 1969
sth that is not governed by VCLT treaty doesn’t mean it is not a treaty
-states and agreements with non-states and other organisations like private companies
Anglo Iranian Oil 1952 ICJ rep 93
Texaco v Libya case, 1977-even in these situations parties can take international rules as general
law
Treaty rules in strictu sensu are not applicable to these agreement bc they are not treaties but as
general rule can be applicable
Peace agreements? CA 3 Geneva Conventions 1949-Syria agreement, Columbia peace
agreement, liberation armies-non-state actors-what’s the legal status of these and are they
governed by treaty law? No concrete answer yet on this-but, agreements allow further
application of international law
Formation and entry into force
-Treaties are result of political process, states decide for a treaty to create it, VCLT was product of ILC
(International Law Commission)
-Authority to conclude treaties: states, who can sign?
-Art 7 VCLT 1969-authority to conclude treaties-heads of states, heads of governments...
-heads of state-president, queen
-heads of governments-prime minister, everyone with executive functions, depends on the
system
-president can expressly give powers to some head of ministry...
4
