This paper argues that whatever reasons we have for developing domestic law also hold for developing international law. I will offer a moral justification for the necessity of developing international law into a legal system that promotes the rule of law. The justification is two-pronged: 1. international law can facilitate mutually beneficial cooperation internationally, and 2. international law is in a position to help those most vulnerable to abuse, oppression, and harm. Although the current operation of international law is flawed and in the early stages of development, we have good evidence that it is moving in the right direction on both dimensions. This justification addresses a long standing skepticism of international which claims international law is superfluous, since we already have well developed systems of national law. I will show that even countries with well-developed systems of law need the predictability and protection that comes with an additional layer of international law.
