International Human Rights Law
THERE ARE TWO SOURCES OF INTERNATIONAL LAW: CUSTOM AND treaties. Customary international law is the term used to describe rules that are so widely accepted and so deeply held that they help to define what it means to belong to a civilized society. The question of whether customary international law is binding on the United States came before the U.S. Supreme Court as long ago as 1900 in a case called Paquete Habana.1 It involved two fishing boats flying the Spanish flag that were seized by armed vessels of the United States during the Spanish-American war as they were fishing along the coast of Cuba. Their American captor sold the two boats at auction. The capture was unlawful under the customs of war, the Supreme Court held, and the proceeds from the sale of the boats, together with damages and costs, should be paid to the Spanish owner of the two boats.
Treaty law—or conventional law, as it is sometimes called, because the treaties that are the source of such law are multilateral conventions (at times, also referred to as covenants)—often covers the same ground as customary international law. Torture is forbidden by customary international law, for example, and prohibitions against torture are also set forth in several multilateral treaties. The effect is to reinforce recognition that a particular norm set forth in a treaty has the status of customary law. On the other hand, not every provision contained in a treaty has the status of customary law. In order for it to attain that status there has to be additional evidence