The Wealth of Nations by Part 4 Chapter 3 Page 72

The trade of Great Britain would be just as advantageous to France, and, in proportion to the wealth, population, and proximity of the respective countries, would have the same superiority over that which France carries on with her own colonies. Such is the very great difference between that trade, which the wisdom of both nations has thought proper to discourage, and that which it has favoured the most.

But the very same circumstances which would have rendered an open and free commerce between the two countries so advantageous to both, have occasioned the principal obstructions to that commerce. Being neighbours, they are necessarily enemies, and the wealth and power of each becomes, upon that account, more formidable to the other; and what would increase the advantage of national