Customary International Law Part II

Customary international law at the time ATS was written is different than our modern understanding of customary international law. Today, there is a larger variety of actions that are seen as violating customary international law. For example, slavery is seen as violating customary international law. When the ATS was written back in the late 1700s slavery was still legal in the United States and in most countries around the globe. Back then, State actors and legal minds would think it crazy to violate slavery. Another example is terrorism. It may seem obvious today that terrorism is condemned, but the definition of terrorism and its growth as a political tool is relatively modern.

As we develop, customary international law will continue to change. The international tribunals, the U.N. and other international bodies are giving more and more weight to international law and the actions of states. In the United States there is a great deal of resistance to customary international law from attorneys, judiciary, legislators and the public. Many people still believe in American Exceptionalism and that we should not use international laws to determine domestic issues. However, that does not mean we cannot use international laws and norms to show contrast or weaknesses in our own laws. Furthermore, some of our oldest laws were based on international norms. Lastly, it is likely only a matter of time for certain customary international laws and norms to become actual laws in the United States.

A reason for this is that as we evolve as a society certain activities are seen as reprehensible or immoral. In order for us as a society to grow and feel better about ourselves we decree certain activities to be illegal. Customary international law is generally on the leading edge of this. Once again see the comments about slavery or terrorism. However, instead of accepting customary international law, US courts and legislators will likely write new laws which incorporate the customary international law into Americanized version.