Langdon-Davies witnessed a great part of the invasion of Finland, and here analyzes the factors that went into that amazing resistance. Scientific method and scientific discipline in the face of the problem of war. A very detailed study of preparation, of adjustment of equipment to climate and geography, of sk tactics, of type of arms, etc. He shows how the fiber of a healthy, enlightened people has been strengthened, while sound economic and social structure provided them with greater power of resistance. An analysis of the manoeuvers, the superior strategy. Little personal material, which limits the distribution chances to those interested in the military science, and the close-up study of mechanized war.