Public International Law I
History and Nature of International
13 September 2013
Definition of international law
body of law which is composed for its greater part of the principles
and rules of conduct which states feel themselves bound to
observe, and therefore, do commonly observe in their relations with
each other, and which includes also:
The rules of law relating to the functioning of international institutions or
organizations, their relations with each other, and their relations with states
Certain rules of law relating to individuals and non states so far as the rights
or duties of such individuals and non-state entities are the concern of the
A brief history of International Law
Ancient time -Imperial Rome’s contribution was the development of:
Jus fatiale consisting of religious rules which governed Rome’s external relations and
formal declarations of war which, inter alia, recognized the inviolability of
ambassadors and was at the origin of the distinction between ‘just’ and ‘unjust’ war;
Jus gentium which governed relations between Roman citizens and foreigners. It
became an essential part of Roman law and thus greatly influenced all European
legal systems and, through them, public international law;
The doctrine of ‘just’ war by Cicero;
The doctrine of the universal law of nature known as ‘natural law’.
The Middle Ages-Two sets of truly international rules developed:
Lex marcatoria which consisted of rules of conduct and fair dealing between
Maritime customary law.
From the 1648 Peace Treaty of Westphalia to the 1815 Congress of
The period of classical international law.
The 1648 Treaty of Westphalia recognized the principles of sovereignty,
territorial integrity and the equality of States.
It legitimized the principle of non-interference in the affairs of a State and
recognized that a State was independent from the church.
The treaty established a system of balance of power which lasted until the
French Revolution and the Napoleonic Wars, and was aimed at preventing
The intellectual support for new ideas was provided by scholars, in particular
the Anglo-Dutch School represented by Hugo Grotius and Alberto Gentilli.
At the end of eighteenth century, the enlightenment ideals supporting the
aspirations of the British colonies in North America fighting for
independence from the British monarchy and supporting the French people
and fighting the France’s monarchist tyranny, feudal aristocratic privileges
and the Catholic clergy had great influence on the development of human
rights and the principle of self determination.
From the 1815 Congress of Vienna to the outbreak of World War 1
(WWI) in 1914
The 1815 Congress of Vienna codified the law on diplomatic agents and
missions, prohibited slave trading and laid the foundations for the free
navigations of rivers which flow through at least two European States.
The main features of international law during the period from 1815 to 1914
were the principles of sovereignty, balance of power, legitimacy and equality
The unorganized character of the international community, which was
composed of a multitude of sovereign States legally equal;
The acceptance of war as the ultimate instrument of enforcing law and
safeguarding national honor and interest;
The recognition of States as the only subjects of international law.
The 19th century was the century of positivism which was introduced by
French philosopher Auguste Compte.
He posited that humanity had gone through three stages of development:
theological which focused on religious idea, the metaphysical which
concentrated on legalistic and jurisprudential ideas; and “positive” which
rejected the past superstitions, ideas and dogmas to focus on scientific
studies of objectively ascertainable facts.
The positivist theories were developed by john Austin and Jeremy Bentham
and came to dominate jurisprudential thinking in general. Including the
theory of international law.
The nature of international law
The status of international law as ‘law’ has been challenged at both the
theoretical by John Austin (1790-1859) and by HLA Hart (1907-1992) and
at the practical level
The main arguments against the existence of international law as ‘law’ is the
international law does not have any legislature, judiciary or executive within
the ordinary understanding of these terms, responsible for creation,
interpretation and enforcement of that law.
The most convincing arguments in favor of the existence of international law
are that States recognize and observe international law with the
consequence that there is substantial order in international relations and the
international law is practiced on a daily basis by international lawyers,
intergovernmental organizations and other non-states actors and applied by
domestic and international courts.
Enforcement of International
The fact that international law has no centralized process of enforcement
does not mean that international law is not obeyed. A state obeys
international law because:
The prospective long-term advantage of compliance prevails over any short
term advantage resulting from violation of international law;
It wants to maintain its good reputation; it fears retaliatory measures or
measures based on reciprocity that may be taken by a victim state (the
three Rs compliance)
The UNSC may take various measures, including the use of force, under
Chapter VII of the UN Charter to force a State to comply with international
It is bound under many international treaties to accept the compulsory
jurisdiction and the judgments of a body established by treaty to deal with
disputes arising out of it;
It fears public opinion both at home and abroad.
Situations to which international
law is relevant
Co-operation-States are naturally independent in many ways and
international law facilitates co-operation;
Co-existence- States have to co-exist with one another and a way of
facilitating this is to define their relationship by making treaties and other
Conflict-Here, the role of international law is confined to two main functions,
i.e. the prescribing of technical rules of conduct and the keeping of any
conflict to a minimum.