His work is fairly typical of his class and era, portraying a way of life and ethos of clubland snobbery that gives an insight into the values of the time, good and bad. His leading characters are all dyed-in-the-wool supporters of Royalty, Empire and the class system and many of his villains are villainous because they attack these ideas, although in
The Golden Spaniard he pits various protagonists against each other in the setting of the Spanish Civil War. His works are enjoyable thrillers, and his "Roger Brook" series in particular offer the reader "history without tears" (Wheatley, in the introduction to
The Man Who Killed the King). His historical analysis is coloured by his politics, but is well informed. For example,
Vendetta in Spain (pre-WWI adventure in that country) contains a discussion of political anarchism which is well grounded, though unsympathetic. His strong attachment to personal liberty also informs much of his work. This, as well as a sympathetic attitude toward Jews (as shown in the 'Simon Aron' character introduced in 'Three Inquisitive People') led him to mercilessly flay the Nazi system in those 'Gregory Sallust' thrillers set in World War Two.
In the winter of 1947 Wheatley penned 'A Letter to Posterity' which he buried in an urn at his country home. The letter was intended to be discovered some time in the future (but was found in 1969 when that home was demolished for redevelopment of the property). In it he predicted that the socialist reforms introduced by the post-war government would inevitably lead to an unjust state, and called for both passive and active resistance to it.
- "Socialist ‘planning’ forbids any man to kill his own sheep or pig, cut down his own tree, put up a wooden shelf in his own house, build a shack in his garden, and either buy or sell the great majority of commodities — without a permit. In fact, it makes all individual effort an offence against the state. Therefore, this Dictatorship of the Proletariat, instead of gradually improving the conditions in which the lower classes live, as has been the aim of all past governments, must result in reducing everyone outside the party machine to the level of the lowest, idlest and most incompetent worker.
- [...]
- It will be immensely difficult to break the stranglehold of the machine, but it can be done, little by little; the first step being the formation of secret groups of friends for free discussion. Then numbers of people can begin systematically to break small regulations, and so to larger ones with passive resistance by groups of people pledged to stand together — and eventually the boycotting, or ambushing and killing of unjust tyrannous officials."
- :Dennis Wheatley, A Letter to Posterity