Operations of international trade law are transacted on two levels--that of public law and that of private law. This distinction is clearly drawn in the Report of the Secretary-General of the United Nations on "The Progressive Development of the Law of International Trade," a report which, it may be recalled, preceded the establishment of the United Nations Commission on International Trade Law (UNCI-TRAL) in December 1966. That report limits its ambit to the "law of international trade," which is defined as "the body of rules governing commercial relationships of a private law nature involving different countries." The report excludes from its examination
"international relations on the level of public law, such as those relating to the attitude and behaviour of States when regulating, in the exercise of their sovereign power, the conduct of trade affecting their territories. Illustrations of commercial relationships of this type are bilateral treaties of commerce or multilateral treaties, such as the General Agreement on Tariffs and Trade (GATT) or the Rome Treaty establishing the European Economic Community."
This distinction is sometimes expressed in another fashion; it is said that the private law relations deal with the micro-economic aspect of international trade and the public law relations with the macro-economic aspect of trade.
Clive M. Schmitthoff,
Commercial Treaties and International Trade Transactions in East-West Trade,
20 Vanderbilt Law Review
Available at: https://scholarship.law.vanderbilt.edu/vlr/vol20/iss2/6