Oppenheimer definition of international law: Law of nations or international law is the name for the body of customary and conventional rules which are considered binding by civilised States in their intercourse with each other.
It is the 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:
1. International institutions
2. Non states entities.
Thus the definition of stark is wider in scope. The main aim of international law is to evolve an ordered rather a just system to regulate international relations. To ensure justice is done between States objectively.
It is observed that States do not deny the international law as such but challenges rules of international law accordingly to their national interest. For example, India invaded Goa under Article 1 (2) of the Charter, even though use of force is prohibited under 2 (4). Therefore, international law governing their relations inter se and ipso facto binding upon them, it would be pedantic not to consider such a body of rules as “true law”.
Generally, international law was termed as weak law, not a true law, law improperly so called, positive international morality, vanishing point of jurisprudence based on its weakness alone. They critic failed to see its potentials ans huge benefits it can bring to the international community. The critics claimed due to the lack of legislative body, hierarchy of courts, absence of proper legal system etc. particular, Austin described international law as a positive international morality which consist of opinions or sentiments current among nations generally.
Moreover, the 1945 UN formation and the independence of States i.e. birth of new states in international law had revolutionised the whole idea of colonised international law to accommodate the idea of emerging countries who favoured human rights, sovereign equality of states, friendly relations etc. thus, international law has experience paradigm shift during the 1945-1970s.