Public International Law
Table of contents
History and Nature of IL (class 1) ................................................................................................................2
A brief History of International Law .........................................................................................................3
The scope and the content of international law .......................................................................................5
Definition of International Law ................................................................................................................9
Function of International law ................................................................................................................10
Sources of IL (class 2) ..............................................................................................................................12
Thinking about international law’s sources ............................................................................................12
Distinction between primary and secondary sources + understanding the most important sources ........14
Beyond article 38 sources of International law?.....................................................................................28
Hierarchy (class 3) ...................................................................................................................................31
Hierarchy in international law ...............................................................................................................31
Defining and understanding jus cogens .................................................................................................32
Preremptory norms ..............................................................................................................................35
Implications of jus cogens ....................................................................................................................37
The states in PIL (class 4) .........................................................................................................................45
Meaning of international legal personality .............................................................................................45
Participants in the International Legal System .......................................................................................45
Criteria for statehood ...........................................................................................................................48
Recognition of states............................................................................................................................59
The law of treaties (class 5) ......................................................................................................................68
The creation of treaties .........................................................................................................................68
Entry in force of treaties........................................................................................................................73
The nature of treaty obligations .............................................................................................................73
Treaty interpretation .............................................................................................................................75
Reservations to treaties ........................................................................................................................77
Invalidity of treaties ..............................................................................................................................83
Suspension & termination of treaties ....................................................................................................85
Jurisdiction in Public International Law (class 6) .......................................................................................86
Defining ‘Jurisdiction’ ...........................................................................................................................86
Case of the SS Lotus (1927, PCIJ) ..........................................................................................................87
Different principles (territorial, personal, universality,…) ........................................................................88
Case study: Belgium and universal jurisdiction......................................................................................92
Treaty-based extensions of jurisdiction .................................................................................................93
Immunities (class 7) ................................................................................................................................ 95
1
, State immunity: Elements of a plea .......................................................................................................95
Immunities (and certain categories of it) ...............................................................................................97
R v Bow Street Magistrates, ex parte Pinochet...................................................................................... 107
Exceptions to immunity ...................................................................................................................... 108
State responsibility (class 8)................................................................................................................... 112
Classification and characterisation of State responsibility ................................................................... 113
Breach of an international obligation of a state .................................................................................... 115
Attribution of conduct to a State ......................................................................................................... 118
Cessation and reparation ................................................................................................................... 127
Diplomatic Protection (class 9) .............................................................................................................. 128
Bases for diplomatic protection .......................................................................................................... 129
Modalities for establishing legal interest ............................................................................................. 131
Questions of nationality: individuals ................................................................................................... 133
Nottebohm (1955), ICJ........................................................................................................................ 134
Diplomatic protection for shareholders............................................................................................... 136
Dispute settelement and the ICJ (class 10) ............................................................................................. 140
International disputes ........................................................................................................................ 140
Diplomatic methods (negotiation, mediation, inquiry, conciliation, arbitration) .................................... 141
The ICJ ............................................................................................................................................... 146
Countermeasures and Sanctions (class 11) ............................................................................................ 154
Non-forcible measures....................................................................................................................... 155
Countermeasures .............................................................................................................................. 157
Acts of retorsion................................................................................................................................. 161
Sanctions .......................................................................................................................................... 162
Use of force & collective security (class 12) ............................................................................................ 164
Use of force definition and art. 2(4) UN Charter ................................................................................... 165
Article 51 UN Charter and armed attack .............................................................................................. 168
Humanitarian intervention.................................................................................................................. 175
Responsibility to protect and the Security Council............................................................................... 179
Collective security and Chapter VII ..................................................................................................... 179
Law of Armed Conflict (class 13) ............................................................................................................ 182
International Human Rights Law (class 14) ............................................................................................. 201
International Criminal Law (class 15)...................................................................................................... 212
History and Nature of IL (class 1)
Today’s lecture (structure)
o A Brief History of International Law
o The Scope and Content of International Law
2
, o A Definition of International Law
o The Function of International Law
A brief History of International Law
International law: portrayed as a legal framework to govern the relations between ‘States’ (=entities which are
the primary subjects of international law)
Public international law private international law (regulates the conflicts between rules of different
domestic legal orders, rather than relations between States, which is reserved for public international law)
o Modern international law begins with the 1648 Peace of Westphalia (termination of the religious
wars) (p5 book)
o Peace of Westphalia: definitive rejection of the secular power of the Pope over internal
affairs of other states => resulting in Catholic and Protestant States being sovereign and
equal, under no higher power
o This historically untrue for some concepts => didn’t begin then; not that people ran like
savages before 1648
o Problematic view to think that civilization began with treaty solving war in Europe => this
view is due to emperialism, european hegemony and colonialism
o BUT it’s important to bear in mind that this is a fiction; we receive myths about the
foundation of our system
o SO dont take 1648 as foundation of int law (has existed for much longer)
o However, different communities and societies have interacted with each other since ‘time
immemorial’
o UN headquarters: replica stone tablet = eternal treaty between Egyptic and Hittite empire
=> 12 b.C. (p4 book)
o => binding agreement between states to recognize eachother immunities
(concrete agreements to respect the immunity,…) => early manifestation of
international law + not western
o Political communities: always implied (impliciete ongeschreven regels) rules on the
bindingness of an agreement, limits of power of one group by the other,…
o Also before Geneva Conventions there were already rules on ethical boundaries that can
be invoked in war time => you don’t need a treaty provision in modern form to know
that there are limits
o Even laws in Europe were fed by political experimentation and practices from outside
Europe => basic notions
o If you go to East Asia, Latin America => evidence of practices and contributions to the
international law we have rn
o There is much to be said about international law outside the Western world
o Euro-centric international law today has roots in European expansion from 1492-1914
Intellectual currents in international law pre-1500
Matter of historical fact that through European Globalization certain structures became the ones on which
the UN was build
o Tension between the particular and universal (tension within international law, hardly exclusive to
Europe)
o = tension between one and many
o Aristotelian idea of kosmopolis permeating (doordringen) much mediaeval scholarship
o Greece is not an ancient country, even though its civilization is => Greece was divided in
100s independent communities (=the citystates) (so Greece was not a state but
civilization were communities operated between one and another)
3
, o Aristotle: irrespective of how we choose the governors, there is something universal about
the civilized world sharing structural ties that transcent the day-to-day necessities of
trade, war, peace time,… => universality (=civilized communities sharing some elements
of humanity that dominated discourses on how the communities (city-states) should
interact)
o Ideal of ‘one community’ embraced by the Christian Church, transformed into jus naturale
o Roman Catholic Church: idea universality is very usefull to them, with catholic being a
connotation that it applies to everyone
o Rooted in natural law (whatever we come up with is part of higher rules: Gods rules)
o Ius naturale (linked to Gods will): distinguishing it from ius gentium (=folks law)
o Natural law was the law people couldn’t touch
o Tension between natural law vs people’s law was already existing before 1648 => even
then there was a claim of universality (pope could do a lot) => degree unification from
outside (through merging political communities)
o E.g. England after it left the church: the real difficulty was not about which God you
believe in but about who decides (we in the country or someone in Rome)
o Jus Gentium—the law of peoples—marginalised during mediaeval epoch
o Yet murmurs of ‘modern’ international law in Italian city-States1
o Protestant Reformation struck discord in the unity of Western Europe
o Martin Luther: theses nailed on church => protestant reformation: crisis that went well
beyond faith => was against power catholic church as an institution to mediate
relationship between people and God
o Direct challenge to ability of the Church and the pope
o Some choices were about whether you went to war against ottoman empire,
whether this treaty with neighbour was lawful/unlawful,.. => protest against
supremacy of the Church (want de kerk had hierop dus een rechtstreekse impact)
o Challenged the authority of the Holy Roman Empire and the Catholic Church
o Protestant rulers began asserting sovereignty independent from Empire and Church
o Fractured western europe (claim supremacy catholic europe vs rejection of it by
protestant europe) => for belgians this is the foundation of our country (north = rebelled
against king of spain and protestants overthrew the spanish catholic rules and
established the dutch republic; catcholic low countries (zuidelijke nederlanden) rejected
this rejection of universality and choose both to remain within empire + remain catholic)
o Border that disects two dutch-speaking territories comes from this conflict
o Series of religious wars culminating with the Peace of Westphalia, 1648
o Western europe when colonizing, was driven by this conflict (reformation) that
reconfigured the map + gave debates about resources and governance => peace of
westphalia
o =series of treaties in which borders were redrawn, settlements were made +
crucial principles came to recognize for very first time and those are relevant in
international law
o Cuius regio eius religio (‘whose realm, his religion’)
o Whoever reigns gets to choose its own religion => power to make our own choices => first
time sovereignity was recognized in treaty making2
1
This phrase means that early signs or beginnings (“murmurs”) of what we now call modern international law were already emerging during the
Renaissance in the Italian city-states (like Venice, Florence, Milan, and Genoa), even before formal international law existed.
What was special about the Italian city-states?
• Between the 13th and 15th centuries, these cities were economically powerful, politically independent, and heavily involved in international
trade, diplomacy, and war.
• They acted like mini-states, with their own governments, armies, and foreign policies.
2
Cuius regio, eius religio was established by the Peace of Augsburg (1555), granting rulers the right to determine the religion of their territories. The Peace
of Westphalia (1648) did not introduce this principle but reinforced and expanded it, recognizing additional denominations and emphasizing state
4
Table of contents
History and Nature of IL (class 1) ................................................................................................................2
A brief History of International Law .........................................................................................................3
The scope and the content of international law .......................................................................................5
Definition of International Law ................................................................................................................9
Function of International law ................................................................................................................10
Sources of IL (class 2) ..............................................................................................................................12
Thinking about international law’s sources ............................................................................................12
Distinction between primary and secondary sources + understanding the most important sources ........14
Beyond article 38 sources of International law?.....................................................................................28
Hierarchy (class 3) ...................................................................................................................................31
Hierarchy in international law ...............................................................................................................31
Defining and understanding jus cogens .................................................................................................32
Preremptory norms ..............................................................................................................................35
Implications of jus cogens ....................................................................................................................37
The states in PIL (class 4) .........................................................................................................................45
Meaning of international legal personality .............................................................................................45
Participants in the International Legal System .......................................................................................45
Criteria for statehood ...........................................................................................................................48
Recognition of states............................................................................................................................59
The law of treaties (class 5) ......................................................................................................................68
The creation of treaties .........................................................................................................................68
Entry in force of treaties........................................................................................................................73
The nature of treaty obligations .............................................................................................................73
Treaty interpretation .............................................................................................................................75
Reservations to treaties ........................................................................................................................77
Invalidity of treaties ..............................................................................................................................83
Suspension & termination of treaties ....................................................................................................85
Jurisdiction in Public International Law (class 6) .......................................................................................86
Defining ‘Jurisdiction’ ...........................................................................................................................86
Case of the SS Lotus (1927, PCIJ) ..........................................................................................................87
Different principles (territorial, personal, universality,…) ........................................................................88
Case study: Belgium and universal jurisdiction......................................................................................92
Treaty-based extensions of jurisdiction .................................................................................................93
Immunities (class 7) ................................................................................................................................ 95
1
, State immunity: Elements of a plea .......................................................................................................95
Immunities (and certain categories of it) ...............................................................................................97
R v Bow Street Magistrates, ex parte Pinochet...................................................................................... 107
Exceptions to immunity ...................................................................................................................... 108
State responsibility (class 8)................................................................................................................... 112
Classification and characterisation of State responsibility ................................................................... 113
Breach of an international obligation of a state .................................................................................... 115
Attribution of conduct to a State ......................................................................................................... 118
Cessation and reparation ................................................................................................................... 127
Diplomatic Protection (class 9) .............................................................................................................. 128
Bases for diplomatic protection .......................................................................................................... 129
Modalities for establishing legal interest ............................................................................................. 131
Questions of nationality: individuals ................................................................................................... 133
Nottebohm (1955), ICJ........................................................................................................................ 134
Diplomatic protection for shareholders............................................................................................... 136
Dispute settelement and the ICJ (class 10) ............................................................................................. 140
International disputes ........................................................................................................................ 140
Diplomatic methods (negotiation, mediation, inquiry, conciliation, arbitration) .................................... 141
The ICJ ............................................................................................................................................... 146
Countermeasures and Sanctions (class 11) ............................................................................................ 154
Non-forcible measures....................................................................................................................... 155
Countermeasures .............................................................................................................................. 157
Acts of retorsion................................................................................................................................. 161
Sanctions .......................................................................................................................................... 162
Use of force & collective security (class 12) ............................................................................................ 164
Use of force definition and art. 2(4) UN Charter ................................................................................... 165
Article 51 UN Charter and armed attack .............................................................................................. 168
Humanitarian intervention.................................................................................................................. 175
Responsibility to protect and the Security Council............................................................................... 179
Collective security and Chapter VII ..................................................................................................... 179
Law of Armed Conflict (class 13) ............................................................................................................ 182
International Human Rights Law (class 14) ............................................................................................. 201
International Criminal Law (class 15)...................................................................................................... 212
History and Nature of IL (class 1)
Today’s lecture (structure)
o A Brief History of International Law
o The Scope and Content of International Law
2
, o A Definition of International Law
o The Function of International Law
A brief History of International Law
International law: portrayed as a legal framework to govern the relations between ‘States’ (=entities which are
the primary subjects of international law)
Public international law private international law (regulates the conflicts between rules of different
domestic legal orders, rather than relations between States, which is reserved for public international law)
o Modern international law begins with the 1648 Peace of Westphalia (termination of the religious
wars) (p5 book)
o Peace of Westphalia: definitive rejection of the secular power of the Pope over internal
affairs of other states => resulting in Catholic and Protestant States being sovereign and
equal, under no higher power
o This historically untrue for some concepts => didn’t begin then; not that people ran like
savages before 1648
o Problematic view to think that civilization began with treaty solving war in Europe => this
view is due to emperialism, european hegemony and colonialism
o BUT it’s important to bear in mind that this is a fiction; we receive myths about the
foundation of our system
o SO dont take 1648 as foundation of int law (has existed for much longer)
o However, different communities and societies have interacted with each other since ‘time
immemorial’
o UN headquarters: replica stone tablet = eternal treaty between Egyptic and Hittite empire
=> 12 b.C. (p4 book)
o => binding agreement between states to recognize eachother immunities
(concrete agreements to respect the immunity,…) => early manifestation of
international law + not western
o Political communities: always implied (impliciete ongeschreven regels) rules on the
bindingness of an agreement, limits of power of one group by the other,…
o Also before Geneva Conventions there were already rules on ethical boundaries that can
be invoked in war time => you don’t need a treaty provision in modern form to know
that there are limits
o Even laws in Europe were fed by political experimentation and practices from outside
Europe => basic notions
o If you go to East Asia, Latin America => evidence of practices and contributions to the
international law we have rn
o There is much to be said about international law outside the Western world
o Euro-centric international law today has roots in European expansion from 1492-1914
Intellectual currents in international law pre-1500
Matter of historical fact that through European Globalization certain structures became the ones on which
the UN was build
o Tension between the particular and universal (tension within international law, hardly exclusive to
Europe)
o = tension between one and many
o Aristotelian idea of kosmopolis permeating (doordringen) much mediaeval scholarship
o Greece is not an ancient country, even though its civilization is => Greece was divided in
100s independent communities (=the citystates) (so Greece was not a state but
civilization were communities operated between one and another)
3
, o Aristotle: irrespective of how we choose the governors, there is something universal about
the civilized world sharing structural ties that transcent the day-to-day necessities of
trade, war, peace time,… => universality (=civilized communities sharing some elements
of humanity that dominated discourses on how the communities (city-states) should
interact)
o Ideal of ‘one community’ embraced by the Christian Church, transformed into jus naturale
o Roman Catholic Church: idea universality is very usefull to them, with catholic being a
connotation that it applies to everyone
o Rooted in natural law (whatever we come up with is part of higher rules: Gods rules)
o Ius naturale (linked to Gods will): distinguishing it from ius gentium (=folks law)
o Natural law was the law people couldn’t touch
o Tension between natural law vs people’s law was already existing before 1648 => even
then there was a claim of universality (pope could do a lot) => degree unification from
outside (through merging political communities)
o E.g. England after it left the church: the real difficulty was not about which God you
believe in but about who decides (we in the country or someone in Rome)
o Jus Gentium—the law of peoples—marginalised during mediaeval epoch
o Yet murmurs of ‘modern’ international law in Italian city-States1
o Protestant Reformation struck discord in the unity of Western Europe
o Martin Luther: theses nailed on church => protestant reformation: crisis that went well
beyond faith => was against power catholic church as an institution to mediate
relationship between people and God
o Direct challenge to ability of the Church and the pope
o Some choices were about whether you went to war against ottoman empire,
whether this treaty with neighbour was lawful/unlawful,.. => protest against
supremacy of the Church (want de kerk had hierop dus een rechtstreekse impact)
o Challenged the authority of the Holy Roman Empire and the Catholic Church
o Protestant rulers began asserting sovereignty independent from Empire and Church
o Fractured western europe (claim supremacy catholic europe vs rejection of it by
protestant europe) => for belgians this is the foundation of our country (north = rebelled
against king of spain and protestants overthrew the spanish catholic rules and
established the dutch republic; catcholic low countries (zuidelijke nederlanden) rejected
this rejection of universality and choose both to remain within empire + remain catholic)
o Border that disects two dutch-speaking territories comes from this conflict
o Series of religious wars culminating with the Peace of Westphalia, 1648
o Western europe when colonizing, was driven by this conflict (reformation) that
reconfigured the map + gave debates about resources and governance => peace of
westphalia
o =series of treaties in which borders were redrawn, settlements were made +
crucial principles came to recognize for very first time and those are relevant in
international law
o Cuius regio eius religio (‘whose realm, his religion’)
o Whoever reigns gets to choose its own religion => power to make our own choices => first
time sovereignity was recognized in treaty making2
1
This phrase means that early signs or beginnings (“murmurs”) of what we now call modern international law were already emerging during the
Renaissance in the Italian city-states (like Venice, Florence, Milan, and Genoa), even before formal international law existed.
What was special about the Italian city-states?
• Between the 13th and 15th centuries, these cities were economically powerful, politically independent, and heavily involved in international
trade, diplomacy, and war.
• They acted like mini-states, with their own governments, armies, and foreign policies.
2
Cuius regio, eius religio was established by the Peace of Augsburg (1555), granting rulers the right to determine the religion of their territories. The Peace
of Westphalia (1648) did not introduce this principle but reinforced and expanded it, recognizing additional denominations and emphasizing state
4
