An editor's note on page 402 of For Want of a Nail ... explains that in 1965, the North American and Mexican Historical Associations agreed that "any work of history written by a scholar of one nation about the other" should contain a critique from a scholar of the subject nation. Professor Robert Sobel thus includes a critique written by Professor Frank Dana of the University of Mexico City on pages 402-6 of the book. This was written after the main body of the work was completed, and Professor Sobel did not see it until the book appeared.
Dana begins by criticizing Sobel's oeuvre, here and elsewhere, as derivative. He gives us background on Sobel that does not appear elsewhere in the book -- that Sobel is Australian and is now sponsored by Stanley Tulin, whom Dana calls "probably the most anti-Mexican historian in the world".
Dana notes that For Want of a Nail ... is the fourth dual history of the U.S.M. and C.N.A. to be published in the past decade, and claims that Sobel appears to have drawn much of his material from these earlier works, including Lawrence Gilman's Duel for a Continent (Mexico City, 1959) and Henry Tracey's The United States of Mexico and the Confederation of North America (New York, 1969), which he does not list in his bibliography. There are also several other works, says Dana, which have also left their marks on Sobel's thoughts, which he does not credit as such.
Dana then launches his major criticism -- that the book is biased in favor of Kramer Associates, "Mexico's major enemy today". During the period that Kramer was resident in Mexico, Dana says, Sobel credits all positive developments in the country to K.A.'s influence and blames all negative ones on Mexican political leaders. As a corrective to Sobel's bias, Dana recommends Oscar Jamison's The Struggle for Liberty: Henry, Adams, and the American Rebellion (Melbourne, 1969), a work which also is not found in Sobel's bibliography.
Finally, Dana summarizes what he calls the implicit thesis of Sobel's book. The North American colonists before the Rebellion had two political traditions: a conservative one looking to Britain and a radical utopian one deriving from the French Enlightenment. The C.N.A., in Dana's characterization of Sobel's view, embodies the first tradition and represents "a new kind of pluralistic civilization, a model for the world". The U.S.M., on the other hand, represents a debasement of Jeffersonian utopianism, "so diluted by the Mexican admixture to be unrecognizable".
The critique is dated 17 July 1972.