Regional books of interest this month: “The Winter Army,” by Maurice Isserman (Houghton Mifflin Harcourt) The 10th Mountain Division may have been the most glamorous of all the military units of World War II. It was made up of an elite group of men trained in skiing and mountaineering and was popularized in magazines and newspapers across the country. The problem was that with the exception of a few men who were sent to Alaska, the 10th did little more than train.