Introduction
International law is the body of rules and principles that regulate international subjects in their relations
with each other (primarily between States, but international organisations and individuals can bear
rights and duties under IL as well).
Key principles:
Sovereignty – supreme authority to act within a certain territory in respect of a group of
persons, and to act within the international sphere. Sovereignty is not absolute (governed by
law – legal system grants sovereignty through IL)
Territory – exclusive area within which to exercise powers to the exclusion of other states
Equality – if all states are sovereign, they must be equal from a legal and formal standpoint
Non-intervention – no state should interfere in the internal affairs of another
Consent – allows international organisations to exist, gives international courts jurisdiction
Responsibility – states are responsible for failing to meet their international obligations
History of International Law
It is not clear when IL originated – there have long been agreements between political units, but
relations between sovereign states are newer. Contemporary IL (law governing relations between
States) originated 17th c Europe – Peace of Westphalia is often viewed as the event catalysing the
formation of sovereign States, and consequently the emergence of IL; however, sovereign states existed
much earlier (probably 15th c in Italy). The intellectual ideas of contemporary IL appear in scholarship
from Europe in 15th and 16th centuries. In 1625, Grotius published ‘The law of war and peace’ which was
the first treatment of IL as a systemic body of law applicable specifically to relations between nations.
Vattel’s 1758 ‘The law of nations’ was the first modern treatise on IL.
In 19th c, characteristic features of contemporary IL began to develop – lawmaking through multilateral
conferences, action through international organisations, third-party adjudication. IL expanded outside
Europe, states began to cooperate on initiatives (eg Red Cross), and international adjudication emerged
as the alternative to law.
In 20th c, international law became universal – number of states more than tripled, IL began regulating
new areas of law like peaceful use of outer space, new international organisations formed. IL also
moved to govern the treatment of individuals by states.
Is international law really ‘law’?
1. Ontological Challenge
Austin argued IL was a system of ‘positive morality’ (not law), which assumes sovereignty is an objective
reality; this has been countered by re-conceptualisation of sovereignty as a legal construct – sovereignty
is created by IL, not predating it. Hart compared IL to domestic law, concluded IL is a ‘simple regime of
primary or customary law’ – it is true IL is different from domestic law, but it has formal means of law-
making, courts and tribunals, enforcement. Furthermore, Hart’s argument assumes the conclusion – if
you define law as domestic law, it may not fit, but IL is a different sense of law.
2. Realist challenge
International law is the body of rules and principles that regulate international subjects in their relations
with each other (primarily between States, but international organisations and individuals can bear
rights and duties under IL as well).
Key principles:
Sovereignty – supreme authority to act within a certain territory in respect of a group of
persons, and to act within the international sphere. Sovereignty is not absolute (governed by
law – legal system grants sovereignty through IL)
Territory – exclusive area within which to exercise powers to the exclusion of other states
Equality – if all states are sovereign, they must be equal from a legal and formal standpoint
Non-intervention – no state should interfere in the internal affairs of another
Consent – allows international organisations to exist, gives international courts jurisdiction
Responsibility – states are responsible for failing to meet their international obligations
History of International Law
It is not clear when IL originated – there have long been agreements between political units, but
relations between sovereign states are newer. Contemporary IL (law governing relations between
States) originated 17th c Europe – Peace of Westphalia is often viewed as the event catalysing the
formation of sovereign States, and consequently the emergence of IL; however, sovereign states existed
much earlier (probably 15th c in Italy). The intellectual ideas of contemporary IL appear in scholarship
from Europe in 15th and 16th centuries. In 1625, Grotius published ‘The law of war and peace’ which was
the first treatment of IL as a systemic body of law applicable specifically to relations between nations.
Vattel’s 1758 ‘The law of nations’ was the first modern treatise on IL.
In 19th c, characteristic features of contemporary IL began to develop – lawmaking through multilateral
conferences, action through international organisations, third-party adjudication. IL expanded outside
Europe, states began to cooperate on initiatives (eg Red Cross), and international adjudication emerged
as the alternative to law.
In 20th c, international law became universal – number of states more than tripled, IL began regulating
new areas of law like peaceful use of outer space, new international organisations formed. IL also
moved to govern the treatment of individuals by states.
Is international law really ‘law’?
1. Ontological Challenge
Austin argued IL was a system of ‘positive morality’ (not law), which assumes sovereignty is an objective
reality; this has been countered by re-conceptualisation of sovereignty as a legal construct – sovereignty
is created by IL, not predating it. Hart compared IL to domestic law, concluded IL is a ‘simple regime of
primary or customary law’ – it is true IL is different from domestic law, but it has formal means of law-
making, courts and tribunals, enforcement. Furthermore, Hart’s argument assumes the conclusion – if
you define law as domestic law, it may not fit, but IL is a different sense of law.
2. Realist challenge
