What is "natural wealth," and how can trade be carried on with it unless there are markets for it when worked? Would the writer maintain that markets cannot be permanently or seriously affected by military conquests, especially if conquest be followed by the imposition upon the vanquished of commercial conditions framed in the interests of the victor?... Germany has derived, and continues to derive, great advantages from the most-favored-nation clause which she compelled France to insert in the Treaty of Frankfurt.... Bismarck, it is true, underestimated the financial resilience of France, and was sorely disappointed when the French paid off the indemnity with such astonishing rapidity, and thus liberated themselves from the equally crushing burden of having to maintain the German army of occupation. He regretted not having demanded an indemnity twice as large. Germany would not repeat the mistake, and any country having the misfortune to be vanquished by her in future will be likely to find its commercial prosperity compromised for decades. To which I replied: Will your correspondent forgive my saying that while he talks of half-truths, the whole of this passage indicates the domination of that particular half-truth which lies at the bottom of the illusion with which my book deals? What is a market? Your correspondent evidently conceives it as a place where things are sold. That is only half the truth. It is a place where things are bought and sold, and one operation is impossible without the other, and the notion that one nation can sell for ever and never buy is simply the theory of perpetual motion applied to economics; and international trade can no more be based upon perpetual motion than can engineering. As between economically highly-organized nations a customer must also be a competitor, a fact which bayonets cannot alter. To the extent to which they destroy him as a competitor, they destroy him, speaking generally, and largely, as a customer.