It was 250 years ago that Adam Smith published The Wealth of Nations. In it, he looked back on the contact that various distant peoples had had with Europeans, following the discoveries of Christopher Colombus and Vasco de Gama. The results, by Smith’s time in 1776, had been tragic. Smith writes: “To the natives…all the commercial benefits which can have resulted from those events have been sunk and lost in the dreadful misfortunes which they have occasioned.” Contact can and should, Smith says, be mutually advantageous: “By uniting, in some measure, the most distant parts of the world, by...