” There seem, however, to be two cases in which it will generally be advantageous to lay some burden upon foreign for the encouragement of domestic industry.
“The first is, when some particular sort of industry is necessary for the defence of the country. ...
“The second case, in which it will generally be advantageous to lay some burden upon foreign for the encouragement of domestic industry is, when some tax is imposed at home upon the produce of the latter. In this case, it seems reasonable that an equal tax should be imposed upon the like produce of the former. This would not give the monopoly of the home market to domestic industry, nor turn towards a particular employment a greater share of the stock and labour of the country than what would naturally go to it. It would only hinder any part of what would naturally go to it from being turned away by the tax into a less natural direction, and would leave the competition between foreign and domestic industry, after the tax, as nearly as possible upon the same footing as before it... “
“As there are two cases in which it will generally be advantageous to lay some burden upon foreign for the encouragement of domestic industry, so there are two others in which it may sometimes be a matter of deliberation; in the one, how far it is proper to continue the free importation of certain foreign goods; and in the other, how far, or in what manner, it may be proper to restore that free importation after it has been for some time interrupted.
“The case in which it may sometimes be a matter of deliberation how far it is proper to continue the free importation of certain foreign goods is, when some foreign nation restrains by high duties or prohibitions the importation of some of our manufactures into their country. Revenge in this case naturally dictates retaliation, and that we should impose the like duties and prohibitions upon the importation of some or all of their manufactures into ours. ...
“There may be good policy in retaliations of this kind, when there is a probability that they will procure the repeal of the high duties or prohibitions complained of. The recovery of a great foreign market will generally more than compensate the transitory inconveniency of paying dearer during a short time for some sorts of goods. To judge whether such retaliations are likely to produce such an effect does not, perhaps, belong so much to the science of a legislator, whose deliberations ought to be governed by general principles which are always the same, as to the skill of that insidious and crafty animal, vulgarly called a statesman or politician, whose councils are directed by the momentary fluctuations of affairs. ...
“The case in which it may sometimes be a matter of deliberation, how far, or in what manner, it is proper to restore the free importation of foreign goods, after it has been for some time interrupted, is, when particular manufactures, by means of high duties or prohibitions upon all foreign goods which can come into competition with them, have been so far extended as to employ a great multitude of hands. Humanity may in this case require that the freedom of trade should be restored only by slow gradations, and with a good deal of reserve and circumspection. Were those high duties and prohibitions taken away all at once, cheaper foreign goods of the same kind might be poured so fast into the home-market as to deprive all at once many thousands of our people of their ordinary employment and means of subsistence. The disorder which this would occasion might no doubt be very considerable...
“The undertaker of a great manufacture, who, by the home-markets being suddenly laid open to the competition of foreigners, should be obliged to abandon his trade, would no doubt suffer very considerably. That part of his capital which had usually been employed in purchasing materials and in paying his workmen might, without much difficulty, perhaps, find another employment. But that part of it which was fixed in workhouses, and in the instruments of trade, could scarce be disposed of without considerable loss. The equitable regard, therefore, to his interest requires that changes of this kind should never be introduced suddenly, but slowly, gradually, and after a very long warning...
Adam Smith Wealth of Nations, Book IV Chapter II
Great post and great research.