Growth and Development of International Law

International law in an area that has been of great importance in recent times as it regulates the relations of States, IGO’s, NGO’s and individual persons in their dealings with one another. International law as it is seen in modern times has gone through several developmental states to achieve its present status. There have been several modifications in the scope and subjects of international law as time passes by.

This article divides the growth and development of international law into four main phases. The first phase starts with the peace agreements that was made in Europe after the thirty years war, followed by the second phase with begins after the first Word War and then the third phase which begins after the Second World War and finally the last phase which refers to the aftermath of the Second World War till date. The last part of the article looks at the future of international law and it does this by situating the future of international law in the question as to whether international law is dying or not.

Key Words
International relations
United Nations


The interaction among countries is regulated by international laws and customs and it is for this reason that international law serves a great purpose as far as the international interaction among states is concerned. No country can leave in isolation without depending on other countries for raw materials, national resources, and technological know-how among others and hence there is the inevitable need for countries to depend on one another for survival. This interaction and to a large extent trade relations among member countries, therefore, needs to be guided by some laws which will help to ensure that such interactions are on a peaceful basis with without chaos or possible violence in the international system and hence its essence in contemporary times. Laws that governs relations among states, IGO’s, NGO’s and individual has developed from one stage to the other with significant improvements and changes in their scope and applicability.

Definition of international law
International law was first developed to govern the relations among sovereign countries and as such it was referred to as The Law of Nations. That is to say that a set of rules and regulations meant to regulate the relations among sovereign and civilized states with their dealings and activities among themselves.
This is a narrow definition and viewed by scholars as the traditional definition of international law. Obviously, there are a lot of grey hairs in this definition of international law as it is difficult to determine which state is civilized and which state is not and more importantly, the scope and subjects of international law have in modern times widened to govern the relations of not only sovereign states but that of Non-Governmental Organizations, International Governmental Organizations, and even individual persons as well.

With the proliferation of Non-Governmental organizations (NGO’s) most probably after the WWII as well as the business transactions, agreements and contract among persons, the scope, and definition of international law have widened to cover, NGO’s and even persons as well. In modern times it is defined as a body of rules and principles that govern the relations among States, International Governmental Organizations (IGO’s), NGO’s as well as individual persons in the relations among each other (Egede & Sutch, 2013). This definition of international law is mostly referred to as the modern definition as it expands the scope and focus of international law.

Growth and development of international law
The expansion and development of international law can be divided into four main phases:

The first Phase
The first and perhaps most important phase in the development and expansion of international law began with the Peace of Westphalia which was a peace treaty signed to end the thirty years war that was fought in Europe from 1618-1648. The main participants in that treaty were France and Sweden on one side with their opponents Spain and the Holy Roman Empire on the other side. By the terms of the treaty, each state was to be recognized as sovereign and independent of the Holy Roman Empire making the Holy Roman emperor virtually powerless which subsequently led to the collapse of the Roman Empire.

This event is very important as far the development of international law is concerned as it is seen as the beginning of the concept of sovereignty and independence of states in international law. The treaty conferred sovereignty of all participating states which should be given full recognition by the other members and this concept has remained and perhaps been modified until present times. The Sovereignty and independence of states is a very important concept in contemporary international relations as it entitles each state to be responsible for their internal affairs which should not be infringed upon by other states. By, implication, therefore, it meant that member States are to acknowledge the territorial boundaries of others and not interfere in the affairs of other members in any way.

Also since the thirty years war, which was fought in Europe at that time was both a religious and political war, it was, therefore, important to acknowledge the religious and political freedom of individual as it became obvious that, if individuals are oppressed religiously or politically they will always revolt. The peace treaty which ended the thirty years war thus made provision for such concepts as freedom of association and religion which have also been an important concept in recent international humanitarian laws. Thus, concepts such as freedom of association and religion which form the basic backbone of most humanitarian laws could all the traced back to this peace treaty.

However, the problem that was unsolved by the peace agreement was that the peace agreements reached failed to establish an institution that is expected to be responsible for ensuring that these agreements reached among nation were to be followed without any breach so eventually most of the agreements reached was breached which subsequently lead to Word War 1 and subsequently leading to the second developmental phase.