Traffic and trade among peoples are the prerequisites to any international law. Essentially distinct from them, however, are the right of peoples to traffic and trade with each other and the rules of law governing such international traffic. The aggregate of these rules constitutes the international traffic law.

For a hundred years or longer there have been legal rules regulating international traffic, but in no case was any attempt made to cover more than specific questions as they presented themselves for solution, no need being felt as yet among the peoples for a systematic regulation of the law as a whole.