As described in its author's own words, "Riddle of the Sands" was written as "... a story with a purpose", written from "a patriot's natural sense of duty", which predicted war with Germany and called for British preparedness. The whole genre of "invasion novels" raised the public's awareness of the "potential threat" of Imperial Germany. Although the belief has grown that the book was responsible for the development of the naval base at Rosyth, the novel was published in May 1903, two months after the purchase of the land for the Rosyth naval base was announced in Parliament (5 March 1903) and some time after secret negotiations for the purchase had begun. Although Winston Churchill later credited the book as a major reason why the Admiralty had decided to establish the new naval bases, this seems unlikely. When war was declared he ordered the Director of Naval Intelligence to find Childers, whom he had met when the author was campaigning to represent a naval seat in Parliament, and employ him. At the time Childers was writing "Riddle" he was also contributing to a factual book published by "The Times" in which he warned of outdated British army tactics in the event of "conflicts of the future". He developed this theme in two further works he published in 1911: "War and the Arme Blanche" and "German Influence on British Cavalry".