LECTURE 1. INTRODUCTION, HISTORY AND NATURE OF IR
Exam format en teaching materials
- Exam: open book!
- Course material:
o International law: second edition
o Sourcebook
o Casebook
o Key readings (optional): not mandatory to pass the class. If you not read them, you will
still ‘probably’ pass the class. Will ask for different approaches and perspectives (advised
to read them)
INTRODUCTION
International law vs. national law International = legal framework to
govern the relations between States, the
law between nations.
National = regulating relationships
between individuals or between
individuals and the State.
Public international law vs. private Public = regulates the relations between
international law States
Private = describes the principles that
determine which law is applicable to
situations involving individuals with a
foreign element. It regulates conflicts
between rules of different domestic legal
orders in situations where there is a
choice between the laws of different
countries. (ex. international marriages)
The purposes of international law have evolved over time. It is worthwhile to study its history to know
how international law has assumed its contemporary shape.
1. A BRIEF HISTORY OF INTERNATIONAL LAW
Modern international law begins with the 1648
o Peace of Westphalia: treaty resolving the war between religions.
Some of the principles of Peace of Westphalia are part of the DNA of IL we know now. However,
different communities and societies have interacted with each other since ‘time immemorial’.
Overtime rules have developed to regulate their relations with one another.
o They have signed treaties and alliance and even exchanged diplomats
There is much to be said about international law outside the Western world
o The earliest surviving treaty text was agreed between an Egyptian pharaoh and Hittite
King. In that ‘treaty’ there is a binding agreement to recognise its each other’s
immunities. These are all early manifestation of IL.
o We also have remains of Roman peace treaties.
o In mediaeval Western Europe, after the fall of the Roman Empire, there existed a
patchwork of feudal entities and kingdoms. Over time feudal arrangements made place
for centralized structures, which began to take on the characteristics of a State.
1
, o After the Protestant Reformation in central and northern Europe, in which Calvin and
Luther denounced the ecclesiastical structure of the Roman Catholic Church and papal
supremacy, a number of religious wars plagued Europe, culminating in the 30 years war
(1618-1648). These were terminated with the Peace of Westphalia, the name of several
treaties signed in 1648 and which marks the start of modern international law.
Euro-centric international law today has roots in European expansion from 1492-1914
o Europe took over the world for 500 years in terms of power and war. o the law of the
European countries was seen as the standard and other countries had to adhere to it to
be accepted as international legal actors. That’s why IL is so euro-centric.
2. INTELLECTUAL CURRENTS IN INTERNATIONAL LAW
1. Intellectual currents in international law pre 1500
Through European globalization certain structures became the ones on which the UN has been built.
Intellectual traditions that existed before 1500 => ideas that organised the debate on how the world
should be organised
Aristotelian idea of kosmopolis permeating much mediaeval scholarship
o Aristotele
Greece was initially divided in hundreds of entities (city states). Greece was not
a state but rather a civilization in which communities operated, traded and went
to war.
Aristotele: there is the idea of a civilized world, sharing certain structural ties
that transcend the day-to-day necessities of treaded, war, peace and
consumption
= Idea of kosmopolis = the idea of a polis/universality, a political community
that embraces all, that embraces everyone. Aristotle's idea was that we could
have all the people of the world under one polis, under one government. A
universal government that could set rules for the entire world. This idea was
adopted by the Christian church => we are all united under the kingdom of God.
Ideal of ‘one community’ embraced by the Christian Church, transformed into jus naturale
o The notion of universality would become a unifying factor suggesting that even if we
create a kingdom in Iceland, they are still bound by certain political rules that regulate
these communities.
o Those rules are embedded in Jus naturale/natural law: rules that humans create are
subordinate to higher rules that God has created.
Jus Gentium—the law of peoples—marginalized during mediaeval epoch
o = Idea that people organised themself into smaller communities. Before 1500, that idea
was not very important, the church was utter dominant in Europe and it had the capacity
to remove kings and queens, to force unification between different territories etc. There
was this sense that under ius naturale (the law of nature) one universal community of
Christian people needed to be formed. So ius gentium was quite marginalised during this
period.
o During this period, there was not a lot of concentrated thinking about government and
democracy was not a thing yet. Nevertheless, in Italy we see the beginning of what we
would call international law today. Back then, Italy was not one country, you had several
kingdoms => those kingdoms were trading with each other, exchanging ambassadors,
recognizing the power of each other's king, duke, pope etc. and they were developing
rules between them. These are the murmurs of modern international law.
Yet murmurs of ‘modern’ international law in Italian city-States
2. Intellectual currents in international law (1500-1648)
2
, Protestant Reformation struck discord in the unity of Western Europe
o Started in Europe and it was crisis that went beyond the faith
Challenged the authority of the Holy Roman Empire and the Catholic Church
o as an institution to mediate the relationship between the people and God. Politically, it
was a direct challenge to the ability of the church
Protestant reformation as a protest against the primacy of the church
o Sparked the wars of religions, which fractured the Western Europe
==> The claim of primacy by Catholic Europe the rejection of
primacy/universality by Protestant Europe
Protestant rulers began asserting sovereignty independent from Empire and Church
o As they became more radical, they outright banned the Catholic Church.
Series of religious wars culminating with the Peace of Westphalia, 1648
o The Peace of Westphalia
A series of treaties originating from West Germany in which borders were
withdrawn and settlements were made, but a few absolute crucial principles will
be recognized for the first time.
Cuius regio eius religio (‘whose realm, his religion’)
o Whomever reigns, gets to choose their religion
Take root in ancient philosophy: a rejection of someone else deciding for us from
outside
external, universal claims to something transcending, something beyond
us = first recognition of sovereignty
3. MODERN INTERNATIONAL LAW, 1648-1815
3.1 PEACE OF WESTPHALIA
Consequences of Peace of Westphalia
- Peace of Westphalia
o Westphalia is understood as the starting point for modern IL in Europe. The
peace of Westphalia represented a definitive rejection of the secular power
of the Pope over the internal affairs of other States. States would
henceforth be sovereign and equal in their relations with one another
without external interference unless consent was expressly given.
The sense of jus naturale weakened
- Westphalia was the seed of a decisive move away from a universal law rooted in the
Christian religion => so the sense of jus naturale weakened. We can even speak about
a rebirth of ius gentium.
The sovereignty of each State was affirmed
- Sovereignty of these units meant the rejection of universality, but not totally. It’s rather
the rejection of rules that could have implied to us how they are said and made.
- Under the Peace of Westphalia, each State would be free to choose for itself which
religion to adopt: cuius regio eius religio (whose realm, his religion’). It became a
domestic matter.
The principle of non-interference in the internal affairs of a State was recognized
A series of rules for States to relate to each other began to emerge
Jus Gentium reborn?
We see that the treaties of Westphalia were not only designed to end the war but also to
establish the basis for future relations
3.2 GROTIUS, JUS NATURALE AND JUS GENTIUM
Hugo Grotius (de Groot), based in Leiden
3
, o He was lawyer that contributed inter alia to the depiction of the nature of IL.
Seminal book, De Jure Belli ac Pacis
o In his book On the law of War and Peace, he portrayed IL as a combination of 2
distinct bodies: jus gentium and jus naturale.
International law portrayed as a combination of two distinct bodies, jus gentium and jus naturale
o Jus naturale was the law that ‘existed within nature’, these laws were universal, eternal
and would be discovered through the full use of human reasoning
o Jus gentium, for Grotius, was purely a human creation, subject to change from time to
time, and variable from place to place. Its source of validity was the consent of States
This idea was taken up by Wolff, Pufendorf, Kant; but rejected by Vattel, who focussed only on
relevance of jus gentium
Characteristics of the jus gentium
IL is based on the sovereign equality of States
o IL states in the international legal order are considered equal and sovereign => they are
capable of making their own decisions.
IL is a voluntary system based on consent
o States consent to an obligation. Only if they consent, they are bound. They can make this
decision because they are sovereign.
o non-interference
o States only make rules horizontality in the international legal order
In the Belgian legal order, Parliament passes laws, and they bind all citizens and
all residences => vertical system => up-down
Horizontal system = system where all the legal subjects make the law together. In
the international legal order States create the law that applies between them.
There is no superior authority that stands above them.
The triumph of ius gentium means the rejection of natural justice and other prescriptive
principles (Emer de Vattel): the law is what the States made!
Yet facilitated European colonialism and in the 18th and 19th centuries this gave rise to the
civilizing mission. The idea that the Europe had the best way of governing and the best legal
rules and that it was our duty to give the rest of the world our system.
International will emerge as a system that is essentially horizontal: not centrally governed but
where all the MS have all sovereign states have a stake in law making and obligations can’t be
imposed on them.
This way of thinking gave rise to international legal positivism: the idea that legal rules are
created by human beings through processes.
3.3 DOMINANCE OF POSITIVISM
The 19th century is marked by the emergence of positivism as a dominant way of thinking about IL and
the decisive abandonment of the idea of the law of nature
Positivism is the idea that is drawn from natural sciences. It is the idea that we don’t examine
natural phenomenon by reference to religion or to ethics but rather that we look at something and
try to describe it how it is in reality.
- This idea was also applied to law: we consider what is there and we don’t bring in
non-legal considerations such as politics or religion.
Positivism in international law was a decisive rejection of (external, universal, non-consensual law)
natural law
International law based on sovereign will of States alone:
4
Exam format en teaching materials
- Exam: open book!
- Course material:
o International law: second edition
o Sourcebook
o Casebook
o Key readings (optional): not mandatory to pass the class. If you not read them, you will
still ‘probably’ pass the class. Will ask for different approaches and perspectives (advised
to read them)
INTRODUCTION
International law vs. national law International = legal framework to
govern the relations between States, the
law between nations.
National = regulating relationships
between individuals or between
individuals and the State.
Public international law vs. private Public = regulates the relations between
international law States
Private = describes the principles that
determine which law is applicable to
situations involving individuals with a
foreign element. It regulates conflicts
between rules of different domestic legal
orders in situations where there is a
choice between the laws of different
countries. (ex. international marriages)
The purposes of international law have evolved over time. It is worthwhile to study its history to know
how international law has assumed its contemporary shape.
1. A BRIEF HISTORY OF INTERNATIONAL LAW
Modern international law begins with the 1648
o Peace of Westphalia: treaty resolving the war between religions.
Some of the principles of Peace of Westphalia are part of the DNA of IL we know now. However,
different communities and societies have interacted with each other since ‘time immemorial’.
Overtime rules have developed to regulate their relations with one another.
o They have signed treaties and alliance and even exchanged diplomats
There is much to be said about international law outside the Western world
o The earliest surviving treaty text was agreed between an Egyptian pharaoh and Hittite
King. In that ‘treaty’ there is a binding agreement to recognise its each other’s
immunities. These are all early manifestation of IL.
o We also have remains of Roman peace treaties.
o In mediaeval Western Europe, after the fall of the Roman Empire, there existed a
patchwork of feudal entities and kingdoms. Over time feudal arrangements made place
for centralized structures, which began to take on the characteristics of a State.
1
, o After the Protestant Reformation in central and northern Europe, in which Calvin and
Luther denounced the ecclesiastical structure of the Roman Catholic Church and papal
supremacy, a number of religious wars plagued Europe, culminating in the 30 years war
(1618-1648). These were terminated with the Peace of Westphalia, the name of several
treaties signed in 1648 and which marks the start of modern international law.
Euro-centric international law today has roots in European expansion from 1492-1914
o Europe took over the world for 500 years in terms of power and war. o the law of the
European countries was seen as the standard and other countries had to adhere to it to
be accepted as international legal actors. That’s why IL is so euro-centric.
2. INTELLECTUAL CURRENTS IN INTERNATIONAL LAW
1. Intellectual currents in international law pre 1500
Through European globalization certain structures became the ones on which the UN has been built.
Intellectual traditions that existed before 1500 => ideas that organised the debate on how the world
should be organised
Aristotelian idea of kosmopolis permeating much mediaeval scholarship
o Aristotele
Greece was initially divided in hundreds of entities (city states). Greece was not
a state but rather a civilization in which communities operated, traded and went
to war.
Aristotele: there is the idea of a civilized world, sharing certain structural ties
that transcend the day-to-day necessities of treaded, war, peace and
consumption
= Idea of kosmopolis = the idea of a polis/universality, a political community
that embraces all, that embraces everyone. Aristotle's idea was that we could
have all the people of the world under one polis, under one government. A
universal government that could set rules for the entire world. This idea was
adopted by the Christian church => we are all united under the kingdom of God.
Ideal of ‘one community’ embraced by the Christian Church, transformed into jus naturale
o The notion of universality would become a unifying factor suggesting that even if we
create a kingdom in Iceland, they are still bound by certain political rules that regulate
these communities.
o Those rules are embedded in Jus naturale/natural law: rules that humans create are
subordinate to higher rules that God has created.
Jus Gentium—the law of peoples—marginalized during mediaeval epoch
o = Idea that people organised themself into smaller communities. Before 1500, that idea
was not very important, the church was utter dominant in Europe and it had the capacity
to remove kings and queens, to force unification between different territories etc. There
was this sense that under ius naturale (the law of nature) one universal community of
Christian people needed to be formed. So ius gentium was quite marginalised during this
period.
o During this period, there was not a lot of concentrated thinking about government and
democracy was not a thing yet. Nevertheless, in Italy we see the beginning of what we
would call international law today. Back then, Italy was not one country, you had several
kingdoms => those kingdoms were trading with each other, exchanging ambassadors,
recognizing the power of each other's king, duke, pope etc. and they were developing
rules between them. These are the murmurs of modern international law.
Yet murmurs of ‘modern’ international law in Italian city-States
2. Intellectual currents in international law (1500-1648)
2
, Protestant Reformation struck discord in the unity of Western Europe
o Started in Europe and it was crisis that went beyond the faith
Challenged the authority of the Holy Roman Empire and the Catholic Church
o as an institution to mediate the relationship between the people and God. Politically, it
was a direct challenge to the ability of the church
Protestant reformation as a protest against the primacy of the church
o Sparked the wars of religions, which fractured the Western Europe
==> The claim of primacy by Catholic Europe the rejection of
primacy/universality by Protestant Europe
Protestant rulers began asserting sovereignty independent from Empire and Church
o As they became more radical, they outright banned the Catholic Church.
Series of religious wars culminating with the Peace of Westphalia, 1648
o The Peace of Westphalia
A series of treaties originating from West Germany in which borders were
withdrawn and settlements were made, but a few absolute crucial principles will
be recognized for the first time.
Cuius regio eius religio (‘whose realm, his religion’)
o Whomever reigns, gets to choose their religion
Take root in ancient philosophy: a rejection of someone else deciding for us from
outside
external, universal claims to something transcending, something beyond
us = first recognition of sovereignty
3. MODERN INTERNATIONAL LAW, 1648-1815
3.1 PEACE OF WESTPHALIA
Consequences of Peace of Westphalia
- Peace of Westphalia
o Westphalia is understood as the starting point for modern IL in Europe. The
peace of Westphalia represented a definitive rejection of the secular power
of the Pope over the internal affairs of other States. States would
henceforth be sovereign and equal in their relations with one another
without external interference unless consent was expressly given.
The sense of jus naturale weakened
- Westphalia was the seed of a decisive move away from a universal law rooted in the
Christian religion => so the sense of jus naturale weakened. We can even speak about
a rebirth of ius gentium.
The sovereignty of each State was affirmed
- Sovereignty of these units meant the rejection of universality, but not totally. It’s rather
the rejection of rules that could have implied to us how they are said and made.
- Under the Peace of Westphalia, each State would be free to choose for itself which
religion to adopt: cuius regio eius religio (whose realm, his religion’). It became a
domestic matter.
The principle of non-interference in the internal affairs of a State was recognized
A series of rules for States to relate to each other began to emerge
Jus Gentium reborn?
We see that the treaties of Westphalia were not only designed to end the war but also to
establish the basis for future relations
3.2 GROTIUS, JUS NATURALE AND JUS GENTIUM
Hugo Grotius (de Groot), based in Leiden
3
, o He was lawyer that contributed inter alia to the depiction of the nature of IL.
Seminal book, De Jure Belli ac Pacis
o In his book On the law of War and Peace, he portrayed IL as a combination of 2
distinct bodies: jus gentium and jus naturale.
International law portrayed as a combination of two distinct bodies, jus gentium and jus naturale
o Jus naturale was the law that ‘existed within nature’, these laws were universal, eternal
and would be discovered through the full use of human reasoning
o Jus gentium, for Grotius, was purely a human creation, subject to change from time to
time, and variable from place to place. Its source of validity was the consent of States
This idea was taken up by Wolff, Pufendorf, Kant; but rejected by Vattel, who focussed only on
relevance of jus gentium
Characteristics of the jus gentium
IL is based on the sovereign equality of States
o IL states in the international legal order are considered equal and sovereign => they are
capable of making their own decisions.
IL is a voluntary system based on consent
o States consent to an obligation. Only if they consent, they are bound. They can make this
decision because they are sovereign.
o non-interference
o States only make rules horizontality in the international legal order
In the Belgian legal order, Parliament passes laws, and they bind all citizens and
all residences => vertical system => up-down
Horizontal system = system where all the legal subjects make the law together. In
the international legal order States create the law that applies between them.
There is no superior authority that stands above them.
The triumph of ius gentium means the rejection of natural justice and other prescriptive
principles (Emer de Vattel): the law is what the States made!
Yet facilitated European colonialism and in the 18th and 19th centuries this gave rise to the
civilizing mission. The idea that the Europe had the best way of governing and the best legal
rules and that it was our duty to give the rest of the world our system.
International will emerge as a system that is essentially horizontal: not centrally governed but
where all the MS have all sovereign states have a stake in law making and obligations can’t be
imposed on them.
This way of thinking gave rise to international legal positivism: the idea that legal rules are
created by human beings through processes.
3.3 DOMINANCE OF POSITIVISM
The 19th century is marked by the emergence of positivism as a dominant way of thinking about IL and
the decisive abandonment of the idea of the law of nature
Positivism is the idea that is drawn from natural sciences. It is the idea that we don’t examine
natural phenomenon by reference to religion or to ethics but rather that we look at something and
try to describe it how it is in reality.
- This idea was also applied to law: we consider what is there and we don’t bring in
non-legal considerations such as politics or religion.
Positivism in international law was a decisive rejection of (external, universal, non-consensual law)
natural law
International law based on sovereign will of States alone:
4
