In this volume there is presented a selection -- by no means a ful collection -- of work dealing with frontiers and the historical and recent problems of peoples who live in frontier regions. The original dates of publication cover a spread of thirty years, and it is hardly surprising that in so long a span, when so much material is brought together in one place, two tendencies come to light. On the one hand there is a tendency toward repetition of data and the hardening of ideas; but on the other hand, fortunately, there is a tendency toward growth, development, and a willingness to present material somewhat differently and to modify earlier ideas. In order to make it easier for the reader to form his own opinion on these and other matters, the editorial method adopted has been, first, to divide the studies under geographical and topical headings -- "Inner Asian frontiers", "Sinkiang", "Mongolia", "Manchuria and China", "National minorities", and "Social history" -- and then, under each heading, to present the studies in the chronological order of their original publication.
Each group will be discussed again in a little more detail toward the end of this Preface, but first it seems to be desirable to make it clear that the material as a whole, and the ideas rooted in the material, reflect neither a planned career nor a career grounded in any one of the great academic disciplines, such as geography or history. The simplest way to explain these anomalies is to give a brief account of the turns of circumstance that led the author now toward one aspect of frontier questions, now toward another. Such an account cannot avoid being egocentric, but perhaps it can be kept from becoming egotistic. It may at least be interesting to those who concern themselves with the problems -- never more important than in our time -- of combining study in the classroom and library with observation in the field, because it is impossible since the Second World War for a European, and still more for an American, to live and travel in the frontier territories between China and the Soviet Union -- territories much more vast geographically and more diverse ethnically than the frontier between the United States and Canada -- as I did between the two World Wars and during the Second World War.
Neither the first nor the second time that I went to China did I make the decision for myself, or have any academic purpose in mind. In 1901, when I was less than a year old, my father went out to China to teach in a new program of general Western education adopted by the Chinese government -- then still the Manchu empire. The necessity . . .