Generally speaking, international law is a set of legal principles that governs the relationship between countries. It is derived from treaties, general principles of law recognized in most national legal systems, and other sources.
It is a matter of debate whether the laws of nations can legally control the rights of other nations. Many people believe that only states can voluntarily enter into commitments to international law. However, the Supreme Court of the United States has held that such commitments cannot be unilaterally entered into. In fact, the Supreme Court holds that no nation’s law can legitimately extend beyond its own borders.
International law is also influenced by the concept of international comity. This is the idea that countries should adhere to each other’s norms and practices, in order to maintain good relations. It is not a legal requirement, but it is usually accepted as a means of establishing mutual recognition.
The concept of natural rights was an important part of the 18th century, and remained influential in the politics of the 19th and 20th centuries. These were the times of the republican revolutions in the U.S. During this period, natural rights were particularly important, as they aided in the success of the Constitution.
There is also the concept of supranational law. This occurs when two or more countries cede judicial decisions to a common tribunal. This type of law is sometimes referred to as the rule of recognition. The courts acknowledge a body of rules accepted by nations, and then determine the meaning and applicability of that rule.