Discuss (a) Lex mercatoria

International trade — the exchange of goods-and-services (and capital-and-ideas) across the borders: the imports-and-exports; the supply chains' web (the modern trade's reality — the good made in many countries). The law of international trade — the rules governing those exchanges: the private-law layer (the sales, the transport, the financing, the dispute resolution — the merchant's law) and the public-law layer (the tariffs-and-quotas, the trade agreements, the WTO's world — the state's law). The two layers' unity (the course's map: Units 2-5 and 7 the private; Unit 6 the public; Unit 8 the new).