The term International Law refers to the implicit and explicit agreements binding nation-states, and which system adheres to set values and standards. The difference from other legal systems is in the fact that it applies to international issues between nations or nations and private individuals. Under the banner of International Law, are Public International Law, Private International Law and Supranational Law.
This concept of International Law has existed for hundreds of years, but the more modern understanding of International Law was developed in the mid-19th century, after two World Wars caused the creation of the League of Nations, the International Labor Organization and other organizations responsible for developing standards for international agreements and the conduct of war. The League of Nations was formed as a result of the Treaty of Versailles, after World War I to assist in settling international disputes. However, the advent of World War II proved its lack of overall success and the League was replaced by the United Nations after the war.
The United Nations was created on June 26, 1945. Although there are other international organizations, the UN has become the most influential. Its purpose is to maintain security, promote peace, and generate friendly relations and cooperation internationally. The organization that provides judicial intervention in UN matters is the International Court of Justice.
Public International Law is that area of law that revolves around the relationships of subjects of the International Law, such as the United Nations, maritime law, international criminal law and the Geneva Convention. This also includes sovereign nations and, sometimes, movements within a nation for national liberation or even armed insurgency. These matters are governed by custom, consistent practices, or agreements, such as treaties. On occasion academic or expert legal opinions, as well as accepted standards of human behavior can also be used.
Private International Law (also known as conflict of laws) regards jurisdictional questions, such as where a case may be legally heard and what jurisdictional laws apply to the issues at hand. Private International law deals with conflicts that are between private individuals, and not between states, as in Public International Law.
Supranational law relates to the rights of different sovereign nations and how they are limited as to each other. What Public International Law differ from Supranational Law is the fact that in the Public International Law, nations have surrendered their decision making rights internationally to an outside common institution, like the United Nations.
One example of a situation where sovereign states have created a shared system of governance for the express purpose of social and economic benefit is the European Union. It is not, however, truly supranational, as the member states have retained the option to withdraw from the system at will. Another group of sovereign nations that are in the process of creating a form of supranational law is the East African Community, which includes the states of Kenya, Tanzania, Uganda, Burundi and Rwanda. Their goal is have such a system of governance in place by 2010.