http://mises.org/journals/aen/aen198.asp
AEN: Yet Mises attacks anarchism in no uncertain terms.
HOPPE: His targets here are left-utopians. He attacks their theory that man is good enough not to need an organized defense against the enemies of civilization. But this is not what the private-property anarchist believes. Of course, murderers and thieves exist. There needs to be an institution that keeps these people at bay. Mises calls this institution government, while people who want no state at all point out that all essential defensive services can be better performed by firms in the market. We can call these firms government if we want to.
AEN: The strongest evidence against Mises as a radical anti-statist is the passage in Human Action that endorses conscription.
HOPPE: This passage is very peculiar. It, and the several paragraphs that precede it and the one that follows it, is not in the first edition. It makes its first appearance in the 1963 edition. It comes out of the blue, and has no foundation in his overall thinking. To me, this addition appears completely ad hoc.
You just have to remind yourself about his general position on government. Every group and, if it can be technically done, every individual, can secede from the government. Accordingly, conscription, in this sense, is completely illegitimate. If you read the 1949 edition of Human Action, there is nothing at all that would seem to lead to these particular funny conclusions.
AEN: Perhaps the Cold War explains it.
HOPPE: But the likelihood that he would make a statement like this is the greatest in prior editions. In 1940, he was in Switzerland, surrounded by Nazi forces. In 1949, he had just seen the old Europe smashed by war and imperialism; what better time to endorse the draft so it could be used to stop this type of thing in the future? But he did not. Why, then, does he do this in 1963? There is no major war going on. Vietnam was in its early stages. The Cold War is not at a peak, and the Soviet Union was in its post-Stalinist period. These passages cry out for explanation.
Hoppe writes similar in the intro to Rothbards’ ethics of liberty
also Hulsmann has a section towards the end of “Last Knight of Liberalism” called ‘last clash with anarchists’ (or something like that )