[T]he dominant country can rarely succeed in compelling or inducing a dependency to contribute to the expenses of the supreme government; and, consequently…the dominant country generally defrays from its own resources the expenses caused by the protection of the dependency in peace and in war. These expenses are a disadvantage to the dominant country, even if they should be more than compensated by advantages which it derives from the possession of the dependency. It may be added, that the possession of a dependency often proves a powerful incentive to improvident and useless expenditure on the part of the supreme government.
In consequence of the prevailing errors respecting the nature of the advantages arising from trade, it is usual for the dominant country to grant commercial privileges, by discriminating duties and other similar regulations, to its dependencies… Moreover, as commercial privileges granted by the dominant state to its dependencies imply corresponding prohibitions against other independent states, they provoke the governments of those states to foster the trade and manufactures of their own dominions by granting similar privileges to their own trading and manufacturing subjects. They therefore prevent that extensive commercial intercourse between independent communities, which would not only secure to each of them the greatest possible advantages of a merely economical nature, but would bind them together in mutual amity by the strong ties of common interest.
George Cornewell Lewis
Chapter VIII, Disadvantages Arising to the Dominant Country from the Possession of a Dependency