Despite the name, national law is just one part of the international legal system. National laws may be made by federal legislation, or may be derived from international conventions. The United States Congress and President of the United States may sign or veto federal laws, and these laws are published in the Code of Federal Regulations and United States Code.

Some countries have a tradition of common law. Some states have adopted supranational law. A state may also have a national constitution that integrates international legal obligations into their domestic law.

The law of nations, or jus gentium, is a principle of international law that was first introduced by the German jurist Samuel von Pufendorf. He argued that universal principles should govern nations and persons. He also criticized Hobbes’s notion of war.

During the 18th century, natural rights remained a hot topic in international politics. Emmerich de Vattel, a Swiss jurist, sought to find a middle ground between natural law and international law.

A-national law, or non-state law, has gained popularity in recent years. It is a term used to describe a system of laws that governs commercial transactions whose legality is not based on geographical boundaries. This type of law has been proposed as a replacement for the traditional concept of state law. Some critics of this theory argue that it is a misnomer. Others argue that this is simply wishful thinking.

An example of a-national law would be a ratified convention that directly enforceable by national courts or other implementing authorities. The European Union is one example of a supranational legal system.