Unwritten Law
From a general practice to being binding, and how human rights took advantage of it
Most people think of international law as treaties, documents in multiple languages carried around by people in suits and polished shoes waiting to be signed by some important so-and-so. And they’re half right. A lot of international law involves shuttling papers around, but there’s a key part of international law that’s the exact opposite. This other dimension of law doesn’t even need to technically be written down and could still be binding on States. And, it’s possible this law could sometimes even trump treaties! Today, we dive into customary international law and what it means for human rights.
Customary international law is when there is “a general practice accepted as law”. This means that there is some common behavior that States are following, *and* (this is the tricky part) States accept this general practice as legally binding. You might be wondering how States could think something is legally binding when there is no treaty, contract, or anything in writing. The answer, as the name suggests, is custom.
Well before we had anything like modern international law or States like we know them, we had ambassadors. In the time of ancient Egypt and Greece, we had ambassadors that would operate as envoys from one ruling power to another. To harm one of these people was a great political transgression. In some parts, it was even a religious transgression, for example in ancient Greece, where it was said that these envoys enjoyed the sacred protection of Hermes. This idea that ambassadors should be protected became a universal rule, well before anyone bothered to write a law explicitly saying so.
These types of practices that became expectations are what’s captured in customary international law, and some of those practices relate to human rights. The simple reason that human rights needs customary international law is because treaties only bind States that ratify them. 175 countries have ratified the International Covenant on Civil and Political Rights, but does that mean that countries that haven’t, like Myanmar, Bhutan, South Sudan or Saudi Arabia, are allowed to do anything they want without human rights restrictions? No, because they are still bound by customary international law, and some rules of human rights live in customary international law.
The source we need to look at are the rules of human rights that were explicitly said to not be a binding treaty: the Universal Declaration of Human Rights (UDHR). The UDHR, in simple terms, listed the foundational human rights norms that the world expected after the Second World War. However, for nearly 30 years, there was no human rights treaty to make those norms legally binding. Instead, States started to use the UDHR, incorporating it into their constitutions and courts and raising it in diplomacy. Thus, some of the norms from the UDHR didn’t just become a general practice but they also became things that States expected from each other, a.k.a. they became law!
P.S. Bonus from our personal experience. Gabriel once worked for the United Nations Special Rapporteur on the right to health. A Rapporteur is empowered to hear allegations of violations and then officially request States to respond to said allegations. One such allegation came from Myanmar, which hadn’t ratified the International Covenant on Economic, Social and Cultural Rights. This was a challenge because he couldn’t cite his typical legal basis in his request to Myanmar. Instead, he had to look at the adoption of the right to health in customary international law and use that as the legal basis to request a response.