Perhaps a better title for this book would have been: The Penguin Atlas of Recent Mostly Military History: Europe 1815 to 1980. Much attention is given to military campaigns and political boundaries, but little is said of the populations within the borders, except when they are reduced to population figures. Since the book was published in 1982 and not updated since, you won't find any discussion of the important changes in the past two decades.
The writing style is usually engaging, although the author has the irritating tendency to view nations' developments as a contest to attain the greatest levels of population and industrial production.