INTERNATIONAL LAW
Table of Contents
INTERNATIONAL LAW............................................................................................. 1
⭐ CHAPTER 1 — FOUNDATIONS AND STRUCTURE OF INTERNATIONAL LAW.....3
1.1 Introduction — What International Law Is and Why It’s Different..............4
1.2 A Brief History of International Law...........................................................4
1.3 Structures of International Law.................................................................8
1.4 Basis of International Obligation................................................................9
1.5 International Law vs National Law.............................................................9
1.6 Enforcement of International Law............................................................10
1.7 Critiques of International Law..................................................................11
⭐ CHAPTER 2 — SOURCES OF INTERNATIONAL LAW.......................................11
2.1 Introduction — What are sources of international law?...........................11
2.2 Article 38 ICJ Statute — The classical list of sources...............................12
2.3 Treaties (Conventions)............................................................................12
2.4 Customary International Law...................................................................13
2.5 General Principles as a Source of Law.....................................................16
2.6 Judicial Decisions..................................................................................... 17
2.7 Scholarly Contributions and the ILC.........................................................19
2.8 Unilateral Statements..............................................................................20
2.9 Hierarchy of Sources............................................................................... 22
2.10 Soft Law (Non-binding Instruments)......................................................24
⭐ CHAPTER 3 — THE LAW OF TREATIES..........................................................25
3.1 Introduction — Why treaty law matters...................................................25
3.2 The treaty as a concept under international law.....................................26
3.3 Authority to conclude treaties.................................................................27
3.4 Treaties between states and international organisations........................28
3.5 Consent to be Bound............................................................................... 28
3.6 Entry into Force & Interim Obligations.....................................................30
3.7 Validity of Treaties................................................................................... 30
3.8 Reservations............................................................................................ 31
3.9 Treaty Interpretation............................................................................... 33
3.10 Taking Account of Changes (Amendments & Evolution)........................35
3.11 Termination and Withdrawal.................................................................36
⭐ CHAPTER 4 — THE ACTORS IN THE INTERNATIONAL LEGAL SYSTEM...........37
, 4.1 Introduction — Who are the actors in international law?.........................37
4.2 The State................................................................................................. 38
4.3 International Organisations.....................................................................46
4.4 Individuals............................................................................................... 47
4.5 Other Actors in International Law............................................................47
⭐ CHAPTER 5 — JURISDICTION........................................................................49
5.1 Introduction — What is jurisdiction?........................................................50
5.2 Jurisdiction to Prescribe...........................................................................50
5.3 Jurisdiction to Enforce..............................................................................56
⭐ CHAPTER 7 — STATE RESPONSIBILITY.........................................................57
7.1 Introduction — What is state responsibility?............................................57
7.2 Basic Principles of State Responsibility....................................................58
7.3 Attribution of Conduct............................................................................. 59
7.4 State Responsibility in Relation to Acts of Other States (Art. 16–18
ARSIWA)........................................................................................................ 63
7.5 Circumstances Precluding Wrongfulness (Arts. 20–25)............................63
7.6 Consequences of Wrongful Conduct (Arts. 29–31, 35–38, 40–41)...........68
7.7 Who May Invoke a Breach of International Law?.....................................70
7.8 Diplomatic Protection.............................................................................. 72
7.9 International Responsibility of International Organizations (IOs).............75
⭐ CHAPTER 8 — THE INTERNATIONAL LAW OF THE SEA.................................75
8.1 Introduction............................................................................................. 75
8.2 Sources of International Law of the Sea..................................................76
8.3 Spatial Partitioning of the Sea.................................................................76
8.4 Piracy....................................................................................................... 86
8.5 Conservation of Marine Life.....................................................................87
8.6 Dispute Settlement in the Law of the Sea...............................................88
⭐ CHAPTER 9 — INTERNATIONAL HUMAN RIGHTS LAW..................................89
9.1 Introduction — The Shift From Domestic to International Concern..........89
9.2 Sources of Human Rights Law.................................................................90
9.3 Categories of Human Rights....................................................................90
9.4 Human Rights and Responsibility for Private Acts...................................92
9.5 Enforcement of Human Rights in the United Nations..............................93
9.6 Regional Systems for the Protection of Human Rights............................94
9.7 Human Right to a Healthy Environment – Climate Change & Human
Rights............................................................................................................ 96
9.8 Territorial Scope of Human Rights Treaties.............................................96
, 9.9 Human Rights in Times of Public Emergency..........................................97
9.10 International Protection of Refugees.....................................................98
⭐ CHAPTER 10 — INTERNATIONAL ENVIRONMENTAL LAW..............................99
10.1 Introduction........................................................................................... 99
10.2 From Stockholm to Rio and back to Rio...............................................100
10.3 Sources of International Environmental Law.......................................101
10.4 Basic Principles of International Environmental Law...........................102
10.5 Substantive Regulation........................................................................105
10.6 Implementation and Enforcement.......................................................111
⭐ CHAPTER 11 — INTERNATIONAL ECONOMIC LAW......................................113
11.1 Introduction — What is International Economic Law?..........................113
11.2 Capitalist Basis of the Bretton Woods System.....................................114
11.3 The WTO and International Trade........................................................115
11.4 International Monetary Law (IMF)........................................................117
11.5 International Investment Law..............................................................122
⭐ CHAPTER 12 — THE PEACEFUL SETTLEMENT OF DISPUTES.......................126
12.1 Introduction — Peaceful Settlement as a Core Principle......................126
12.2 Non-Adjudicatory Means......................................................................127
12.3 Arbitration........................................................................................... 128
12.4 The International Court of Justice (ICJ).................................................129
12.5 International Courts & Tribunals with a Specialised Mandate..............135
⭐ CHAPTER 13 — THE INTERNATIONAL REGULATION OF THE USE OF FORCE
....................................................................................................................... 137
13.1 Introduction — Jus ad bellum vs. Jus in bello.......................................137
13.2 The UN Charter & the Prohibition on the Use of Force.........................137
13.3 The Security Council and the Maintenance of International Peace &
Security....................................................................................................... 139
13.4 The Unilateral Use of Force by States — The Right to Self-Defence....144
13.5 — A Plea of Necessity?........................................................................147
13.6 — Contentious Use of Force................................................................148
13.7 — Russia’s Use of Force Against Ukraine (Summary)..........................150
BRONNENBOEK — SHORT SUMMARIES OF CASES & BEPALINGEN..................151
PART 1 — CASES (C-NUMBERS)...................................................................151
PART 2 — BEPALINGEN (B-NUMBERS).........................................................154
⭐ CHAPTER 1 — FOUNDATIONS AND STRUCTURE OF
INTERNATIONAL LAW
,1.1 Introduction — What International Law Is and Why It’s
Different
International law is defined as: “a system of law that regulates the
interrelationship of sovereign States and their rights and duties to one another.”
International law also governs international organisations and individuals,
who can have rights and obligations too.
Unlike national legal systems:
There is no legislature (no world parliament).
There is no executive (no world government).
There is no compulsory court system (states cannot automatically be
forced into court).
There is “no mandatory and well established procedure for the settlement of
legal disputes.”
This means international law is decentralised — states themselves create,
interpret, and enforce the rules.
Because states constantly interact — trade, borders, war, environment, human
rights — and national law cannot solve issues involving more than one sovereign,
international law exist.
The political context
The chapter emphasises that international law reflects the world it operates in:
Historically, cooperation and trust allowed IL to grow.
Recently, trust has declined due to:
o rising non-Western powers (China, Russia)
o political instability in the US and UK
o Brexit
o Trump withdrawing from agreements
o COVID-19
o Russia’s invasion of Ukraine
These events show that IL is shaped by global politics, not separate from it.
1.2 A Brief History of International Law
1.2.1 Early Modern International Law — Natural Law Origins
International law as we know it began in Europe.
The medieval world
,Europe had:
overlapping authorities (Holy Roman Empire, Catholic Church)
transnational communities (knights, merchants)
people who felt loyalty to groups rather than “nations”
Natural law
The dominant idea was natural law:
A universal moral order that applied to all humans — and therefore to rulers.
Natural law “applied to states because rulers are also individuals and therefore
subject to it.”
There was also jus gentium (law of nations), seen as derived from natural law.
Colonial encounters
Spanish theologians debated the rights of indigenous peoples.
Vitoria (1532) argued:
natives were “part of the society of the human race”
and Spanish actions were governed by natural law.
This was the first attempt to apply legal principles to global encounters.
Key thinkers
Francisco Suárez (1612): clarified natural law vs law of nations.
Hugo Grotius (1609, 1625): applied natural law to international relations;
foundational for modern IL.
Emmerich de Vattel (1758): practical guide for diplomats and states.
1.2.2 Peace of Westphalia (1648) — Birth of the Modern State System
This is the single most important historical event in IL.
The Peace of Westphalia:
ended the Thirty Years’ War
reduced the power of empires and the Church
divided Europe into sovereign states with exclusive authority over their
territory
The treaties “compartmentalise territory and individuals into sovereign states.”
Sovereignty
Jean Bodin (1576) defined sovereignty as:
“absolute and indivisible” power, answerable only to God.
This idea was later developed by Hobbes and Locke.
,Westphalia + sovereignty = foundation of modern international law.
1.2.3 The 19th Century — Positivism and State Consent
This era shifts from natural law to positivism.
Positivism
The only source of international law is state will.
“The only true source of law was states’ will.”
This means:
treaties
customary practices states follow because they believe they are legally
required
If a state did not consent, it is not bound.
Why positivism grew
rise of formal international organisations (Telegraph Union 1865, Postal
Union 1874)
first multilateral treaties on war (Paris 1856, St Petersburg 1868)
Hague Conferences (1899, 1907)
colonial expansion and global interaction
Positivism matched a world of sovereign states interacting through agreements.
1.2.4 The Interwar Period — League of Nations
After WWI:
League of Nations created (1919)
aimed to maintain peace
required states to submit disputes before going to war
1928 Treaty of Paris attempted to outlaw war
The Permanent Court of International Justice (PCIJ) was created — the
predecessor of the ICJ.
1.2.5 Post-1945 — The UN System and Modern International Law
This is the most important era for exams.
Nuremberg
Prosecution of Nazi leaders established modern international criminal law.
,United Nations
Replaced the League.
Built on Westphalian principles:
sovereign equality
self-determination
prohibition on the use of force
Security Council can authorise force
Cold War limited the UN’s effectiveness, but after 1991 it became more active.
General Assembly
Not legally binding, but:
global forum
major role in decolonisation
In 1960 it declared colonialism must end “speedy and unconditionally.”
International Law Commission (1946)
Created to codify and develop IL.
ICJ
Replaced PCIJ; became more important over time.
Bretton Woods institutions
IMF
World Bank
GATT → WTO (1995)
These regulate global trade and finance.
Regional organisations
NATO (1949)
EU (from 1951 Coal and Steel Community → Maastricht 1992 →
enlargement 2004)
Council of Europe + ECHR + ECtHR
OAS, AU
Shift in global power
Western-built institutions now challenged by:
SCO (China, Russia, India)
BRICS financial institutions
,1.3 Structures of International Law
1.3.1 International society = sovereign states
Since Peace of Westphalia (1648) → sovereign state = core unit.
International law exists because national law cannot regulate issues
involving more than one sovereign.
International law is a residual system: → It applies only when national
law is inadequate.
Two ways an issue becomes “international”:
1. Content-based (inherent international interest)
→ When states’ interests collide (e.g., borders, use of force, immunity). →
Governed by international law of coexistence.
2. Form-based (made international by treaty)
→ When states choose to regulate something internationally (e.g., human
rights, trade, environment). → Governed by international law of
cooperation.
1.3.2 International Law of Coexistence
Also called general international law.
Covers inherently international issues:
o Territory
o Statehood
o Recognition
o Jurisdiction
o Immunity
o Use of force
o Armed conflict
o Treaty law
o State responsibility
Horizontal structure: regulates relations between sovereign states.
Goal: peaceful coexistence, not deeper integration.
Stable but often vague → requires interpretation and “law-creation” by
courts.
1.3.3 International Law of Cooperation
Much newer (post-1945).
, Covers issues that states choose to regulate internationally:
o EU law
o Human rights
o Environmental law
o Economic law
Optional: states must consent via treaties.
Explains why progress on global issues (poverty, climate change) is slow →
requires consensus.
Focuses on how states exercise authority internally, unlike
coexistence.
1.4 Basis of International Obligation
Why are states bound by international law?
Historical debate:
Natural law → binding because of universal moral principles.
Positivism → binding because states consent.
Modern understanding
No contradiction between sovereignty and obligation.
States accept limits on sovereignty because:
o Peaceful coexistence requires rules.
o All states benefit from stability.
o States never deny being bound by international law — they justify
their actions within it.
Example: Russia in Crimea/Ukraine → argued legality, not that international law
doesn’t bind it.
1.5 International Law vs National Law
International law is supreme
A state cannot justify violating international law by pointing to national
law.
Implementation varies by country
Two classic theories:
Monism
International + national law = one system.
, International law applies directly.
International law prevails in conflict.
Dualism
Two separate systems.
Treaties must be incorporated into national law to have effect.
Modern reality = pluralism
States mix approaches.
Customary international law is often applied directly.
Treaties may require incorporation (e.g., Nordic states, UK).
Courts try to interpret national law consistently with international
obligations.
1.6 Enforcement of International Law
Key point: There is no world police.
But enforcement mechanisms exist:
A. Courts and tribunals
ICJ
PCA
ITLOS
WTO DSB
ICC
Human rights bodies (ECtHR, UN committees)
B. Security Council
Can impose sanctions
Can authorize force
Can create tribunals
But enforcement is political, not purely legal.
C. Self-help by states
Suspension of treaties
Countermeasures
Retorsion (unfriendly but lawful acts)
D. Why states comply anyway
Table of Contents
INTERNATIONAL LAW............................................................................................. 1
⭐ CHAPTER 1 — FOUNDATIONS AND STRUCTURE OF INTERNATIONAL LAW.....3
1.1 Introduction — What International Law Is and Why It’s Different..............4
1.2 A Brief History of International Law...........................................................4
1.3 Structures of International Law.................................................................8
1.4 Basis of International Obligation................................................................9
1.5 International Law vs National Law.............................................................9
1.6 Enforcement of International Law............................................................10
1.7 Critiques of International Law..................................................................11
⭐ CHAPTER 2 — SOURCES OF INTERNATIONAL LAW.......................................11
2.1 Introduction — What are sources of international law?...........................11
2.2 Article 38 ICJ Statute — The classical list of sources...............................12
2.3 Treaties (Conventions)............................................................................12
2.4 Customary International Law...................................................................13
2.5 General Principles as a Source of Law.....................................................16
2.6 Judicial Decisions..................................................................................... 17
2.7 Scholarly Contributions and the ILC.........................................................19
2.8 Unilateral Statements..............................................................................20
2.9 Hierarchy of Sources............................................................................... 22
2.10 Soft Law (Non-binding Instruments)......................................................24
⭐ CHAPTER 3 — THE LAW OF TREATIES..........................................................25
3.1 Introduction — Why treaty law matters...................................................25
3.2 The treaty as a concept under international law.....................................26
3.3 Authority to conclude treaties.................................................................27
3.4 Treaties between states and international organisations........................28
3.5 Consent to be Bound............................................................................... 28
3.6 Entry into Force & Interim Obligations.....................................................30
3.7 Validity of Treaties................................................................................... 30
3.8 Reservations............................................................................................ 31
3.9 Treaty Interpretation............................................................................... 33
3.10 Taking Account of Changes (Amendments & Evolution)........................35
3.11 Termination and Withdrawal.................................................................36
⭐ CHAPTER 4 — THE ACTORS IN THE INTERNATIONAL LEGAL SYSTEM...........37
, 4.1 Introduction — Who are the actors in international law?.........................37
4.2 The State................................................................................................. 38
4.3 International Organisations.....................................................................46
4.4 Individuals............................................................................................... 47
4.5 Other Actors in International Law............................................................47
⭐ CHAPTER 5 — JURISDICTION........................................................................49
5.1 Introduction — What is jurisdiction?........................................................50
5.2 Jurisdiction to Prescribe...........................................................................50
5.3 Jurisdiction to Enforce..............................................................................56
⭐ CHAPTER 7 — STATE RESPONSIBILITY.........................................................57
7.1 Introduction — What is state responsibility?............................................57
7.2 Basic Principles of State Responsibility....................................................58
7.3 Attribution of Conduct............................................................................. 59
7.4 State Responsibility in Relation to Acts of Other States (Art. 16–18
ARSIWA)........................................................................................................ 63
7.5 Circumstances Precluding Wrongfulness (Arts. 20–25)............................63
7.6 Consequences of Wrongful Conduct (Arts. 29–31, 35–38, 40–41)...........68
7.7 Who May Invoke a Breach of International Law?.....................................70
7.8 Diplomatic Protection.............................................................................. 72
7.9 International Responsibility of International Organizations (IOs).............75
⭐ CHAPTER 8 — THE INTERNATIONAL LAW OF THE SEA.................................75
8.1 Introduction............................................................................................. 75
8.2 Sources of International Law of the Sea..................................................76
8.3 Spatial Partitioning of the Sea.................................................................76
8.4 Piracy....................................................................................................... 86
8.5 Conservation of Marine Life.....................................................................87
8.6 Dispute Settlement in the Law of the Sea...............................................88
⭐ CHAPTER 9 — INTERNATIONAL HUMAN RIGHTS LAW..................................89
9.1 Introduction — The Shift From Domestic to International Concern..........89
9.2 Sources of Human Rights Law.................................................................90
9.3 Categories of Human Rights....................................................................90
9.4 Human Rights and Responsibility for Private Acts...................................92
9.5 Enforcement of Human Rights in the United Nations..............................93
9.6 Regional Systems for the Protection of Human Rights............................94
9.7 Human Right to a Healthy Environment – Climate Change & Human
Rights............................................................................................................ 96
9.8 Territorial Scope of Human Rights Treaties.............................................96
, 9.9 Human Rights in Times of Public Emergency..........................................97
9.10 International Protection of Refugees.....................................................98
⭐ CHAPTER 10 — INTERNATIONAL ENVIRONMENTAL LAW..............................99
10.1 Introduction........................................................................................... 99
10.2 From Stockholm to Rio and back to Rio...............................................100
10.3 Sources of International Environmental Law.......................................101
10.4 Basic Principles of International Environmental Law...........................102
10.5 Substantive Regulation........................................................................105
10.6 Implementation and Enforcement.......................................................111
⭐ CHAPTER 11 — INTERNATIONAL ECONOMIC LAW......................................113
11.1 Introduction — What is International Economic Law?..........................113
11.2 Capitalist Basis of the Bretton Woods System.....................................114
11.3 The WTO and International Trade........................................................115
11.4 International Monetary Law (IMF)........................................................117
11.5 International Investment Law..............................................................122
⭐ CHAPTER 12 — THE PEACEFUL SETTLEMENT OF DISPUTES.......................126
12.1 Introduction — Peaceful Settlement as a Core Principle......................126
12.2 Non-Adjudicatory Means......................................................................127
12.3 Arbitration........................................................................................... 128
12.4 The International Court of Justice (ICJ).................................................129
12.5 International Courts & Tribunals with a Specialised Mandate..............135
⭐ CHAPTER 13 — THE INTERNATIONAL REGULATION OF THE USE OF FORCE
....................................................................................................................... 137
13.1 Introduction — Jus ad bellum vs. Jus in bello.......................................137
13.2 The UN Charter & the Prohibition on the Use of Force.........................137
13.3 The Security Council and the Maintenance of International Peace &
Security....................................................................................................... 139
13.4 The Unilateral Use of Force by States — The Right to Self-Defence....144
13.5 — A Plea of Necessity?........................................................................147
13.6 — Contentious Use of Force................................................................148
13.7 — Russia’s Use of Force Against Ukraine (Summary)..........................150
BRONNENBOEK — SHORT SUMMARIES OF CASES & BEPALINGEN..................151
PART 1 — CASES (C-NUMBERS)...................................................................151
PART 2 — BEPALINGEN (B-NUMBERS).........................................................154
⭐ CHAPTER 1 — FOUNDATIONS AND STRUCTURE OF
INTERNATIONAL LAW
,1.1 Introduction — What International Law Is and Why It’s
Different
International law is defined as: “a system of law that regulates the
interrelationship of sovereign States and their rights and duties to one another.”
International law also governs international organisations and individuals,
who can have rights and obligations too.
Unlike national legal systems:
There is no legislature (no world parliament).
There is no executive (no world government).
There is no compulsory court system (states cannot automatically be
forced into court).
There is “no mandatory and well established procedure for the settlement of
legal disputes.”
This means international law is decentralised — states themselves create,
interpret, and enforce the rules.
Because states constantly interact — trade, borders, war, environment, human
rights — and national law cannot solve issues involving more than one sovereign,
international law exist.
The political context
The chapter emphasises that international law reflects the world it operates in:
Historically, cooperation and trust allowed IL to grow.
Recently, trust has declined due to:
o rising non-Western powers (China, Russia)
o political instability in the US and UK
o Brexit
o Trump withdrawing from agreements
o COVID-19
o Russia’s invasion of Ukraine
These events show that IL is shaped by global politics, not separate from it.
1.2 A Brief History of International Law
1.2.1 Early Modern International Law — Natural Law Origins
International law as we know it began in Europe.
The medieval world
,Europe had:
overlapping authorities (Holy Roman Empire, Catholic Church)
transnational communities (knights, merchants)
people who felt loyalty to groups rather than “nations”
Natural law
The dominant idea was natural law:
A universal moral order that applied to all humans — and therefore to rulers.
Natural law “applied to states because rulers are also individuals and therefore
subject to it.”
There was also jus gentium (law of nations), seen as derived from natural law.
Colonial encounters
Spanish theologians debated the rights of indigenous peoples.
Vitoria (1532) argued:
natives were “part of the society of the human race”
and Spanish actions were governed by natural law.
This was the first attempt to apply legal principles to global encounters.
Key thinkers
Francisco Suárez (1612): clarified natural law vs law of nations.
Hugo Grotius (1609, 1625): applied natural law to international relations;
foundational for modern IL.
Emmerich de Vattel (1758): practical guide for diplomats and states.
1.2.2 Peace of Westphalia (1648) — Birth of the Modern State System
This is the single most important historical event in IL.
The Peace of Westphalia:
ended the Thirty Years’ War
reduced the power of empires and the Church
divided Europe into sovereign states with exclusive authority over their
territory
The treaties “compartmentalise territory and individuals into sovereign states.”
Sovereignty
Jean Bodin (1576) defined sovereignty as:
“absolute and indivisible” power, answerable only to God.
This idea was later developed by Hobbes and Locke.
,Westphalia + sovereignty = foundation of modern international law.
1.2.3 The 19th Century — Positivism and State Consent
This era shifts from natural law to positivism.
Positivism
The only source of international law is state will.
“The only true source of law was states’ will.”
This means:
treaties
customary practices states follow because they believe they are legally
required
If a state did not consent, it is not bound.
Why positivism grew
rise of formal international organisations (Telegraph Union 1865, Postal
Union 1874)
first multilateral treaties on war (Paris 1856, St Petersburg 1868)
Hague Conferences (1899, 1907)
colonial expansion and global interaction
Positivism matched a world of sovereign states interacting through agreements.
1.2.4 The Interwar Period — League of Nations
After WWI:
League of Nations created (1919)
aimed to maintain peace
required states to submit disputes before going to war
1928 Treaty of Paris attempted to outlaw war
The Permanent Court of International Justice (PCIJ) was created — the
predecessor of the ICJ.
1.2.5 Post-1945 — The UN System and Modern International Law
This is the most important era for exams.
Nuremberg
Prosecution of Nazi leaders established modern international criminal law.
,United Nations
Replaced the League.
Built on Westphalian principles:
sovereign equality
self-determination
prohibition on the use of force
Security Council can authorise force
Cold War limited the UN’s effectiveness, but after 1991 it became more active.
General Assembly
Not legally binding, but:
global forum
major role in decolonisation
In 1960 it declared colonialism must end “speedy and unconditionally.”
International Law Commission (1946)
Created to codify and develop IL.
ICJ
Replaced PCIJ; became more important over time.
Bretton Woods institutions
IMF
World Bank
GATT → WTO (1995)
These regulate global trade and finance.
Regional organisations
NATO (1949)
EU (from 1951 Coal and Steel Community → Maastricht 1992 →
enlargement 2004)
Council of Europe + ECHR + ECtHR
OAS, AU
Shift in global power
Western-built institutions now challenged by:
SCO (China, Russia, India)
BRICS financial institutions
,1.3 Structures of International Law
1.3.1 International society = sovereign states
Since Peace of Westphalia (1648) → sovereign state = core unit.
International law exists because national law cannot regulate issues
involving more than one sovereign.
International law is a residual system: → It applies only when national
law is inadequate.
Two ways an issue becomes “international”:
1. Content-based (inherent international interest)
→ When states’ interests collide (e.g., borders, use of force, immunity). →
Governed by international law of coexistence.
2. Form-based (made international by treaty)
→ When states choose to regulate something internationally (e.g., human
rights, trade, environment). → Governed by international law of
cooperation.
1.3.2 International Law of Coexistence
Also called general international law.
Covers inherently international issues:
o Territory
o Statehood
o Recognition
o Jurisdiction
o Immunity
o Use of force
o Armed conflict
o Treaty law
o State responsibility
Horizontal structure: regulates relations between sovereign states.
Goal: peaceful coexistence, not deeper integration.
Stable but often vague → requires interpretation and “law-creation” by
courts.
1.3.3 International Law of Cooperation
Much newer (post-1945).
, Covers issues that states choose to regulate internationally:
o EU law
o Human rights
o Environmental law
o Economic law
Optional: states must consent via treaties.
Explains why progress on global issues (poverty, climate change) is slow →
requires consensus.
Focuses on how states exercise authority internally, unlike
coexistence.
1.4 Basis of International Obligation
Why are states bound by international law?
Historical debate:
Natural law → binding because of universal moral principles.
Positivism → binding because states consent.
Modern understanding
No contradiction between sovereignty and obligation.
States accept limits on sovereignty because:
o Peaceful coexistence requires rules.
o All states benefit from stability.
o States never deny being bound by international law — they justify
their actions within it.
Example: Russia in Crimea/Ukraine → argued legality, not that international law
doesn’t bind it.
1.5 International Law vs National Law
International law is supreme
A state cannot justify violating international law by pointing to national
law.
Implementation varies by country
Two classic theories:
Monism
International + national law = one system.
, International law applies directly.
International law prevails in conflict.
Dualism
Two separate systems.
Treaties must be incorporated into national law to have effect.
Modern reality = pluralism
States mix approaches.
Customary international law is often applied directly.
Treaties may require incorporation (e.g., Nordic states, UK).
Courts try to interpret national law consistently with international
obligations.
1.6 Enforcement of International Law
Key point: There is no world police.
But enforcement mechanisms exist:
A. Courts and tribunals
ICJ
PCA
ITLOS
WTO DSB
ICC
Human rights bodies (ECtHR, UN committees)
B. Security Council
Can impose sanctions
Can authorize force
Can create tribunals
But enforcement is political, not purely legal.
C. Self-help by states
Suspension of treaties
Countermeasures
Retorsion (unfriendly but lawful acts)
D. Why states comply anyway
