General Legal Principles and Additional Legal Sources
In the world practice, even though an international agreement has been ratified by law, another law is still needed to implement it in the domain of national law, for example UNCLOS 1982 which was ratified by Law no. 171985 still requires the existence of Law No.6 / 1996 concerning water. On the other hand, there are also international agreements which are ratified but are directly used as a legal basis for implementation, such as the 1961/1963 Vienna Convention on Diplomatic / Consular Relations which is ratified by Law No.1 / 1982. [5]
The status of international treaties in World is non-self-executing because international treaties that have been ratified cannot be implemented directly in national courts before implementing legislation. [6]
International customs
To be able to say that international custom is a source of law there must be the following elements:
There must be a habit that is general in nature,
The habit must be accepted as a law.
For international customs to be international sources, two elements must be fulfilled, each of which can be called a material element and a psychological factor, namely the fact that there is a general habit and the acceptance of international custom as law.
General Legal Principles
General legal principles are the legal principles that underlie the modern legal system. What is meant by the modern legal system is a positive legal system that is based on the principles and legal institutions of the Western state which for the most part are based on the principles and institutions of Roman law.
Additional Legal Sources
Court Decisions and Opinions of Leading Scholars of the Nations in the World.
Court decisions and scholars' opinions are additional sources of subsidies. This means that judicial decisions and opinions of scholars can be put forward to prove the existence of a method of international law regarding an issue based on primary sources, namely international treaties, customs and general legal principles.
The court's decisions and the opinions of the scholars themselves are not binding meaning they cannot lead to a legal method. In the judicial system according to the International Court Charter there is no known principle of a binding court decision (rule of binding precedent). Although court decisions do not have binding power, international court decisions, especially the Permanent International Court of Justice, the International Court of Justice and the Permanent Court of Arbitration have a major influence in the development of international law.
Regarding the second source of additional law, the teachings of prominent legal scholars, it can be said that research and writings conducted by prominent scholars can often be used as a guide or guide to discover what is international law, even though the teachings of the scholars themselves does not cause law. An example is the opinion of prominent legal scholars who are members of the United Nations International Law Commission.
Decisions of Equipment Bodies (Organs) of International Organizations and Institutions
The emergence of various international intergovernmental organizations both universal and regional has a major influence in the development of international law. This is due to the fact that these organizations through their equipment bodies, both the legislative, executive and judiciary bodies, have the authority to issue various decisions, which apply to the organization itself, as well as those that apply to its members, even though the decisions of the organization have not been able to said to be a source of international law.
Theories of International Law
The theory of natural law
he theory of natural law (natural law) is the oldest theory. This teaching has had a profound influence on international law since its growth. According to adherents of the teachings of natural law, international law is binding because:
International law is none other than "natural law" which is applied to the lives of nations, or in other words,
The country is bound or subject to international law in the relationship between them with each other, because international law is part of the highest law, namely natural law. [1]
Theory of Positivism
This flow bases the binding force on international law on the will of the country itself to submit to international law. According to positivists, "basically the state is the source of all law, and international law is binding because the country wants to submit to international law on its own accord". The theory of the will / will of this country also has weaknesses, namely:
They cannot satisfactorily explain how international law which depends on the will of the country can bind the states;
What if a country unilaterally cancels its intention to be bound by the law?
This theory cannot answer the question, why is a newly independent country standing in the midst of the international community already bound by international law, irrespective of whether or not to submit to the law?
This theory also cannot explain the existence of customary law which binds countries.