National Review has a reminder from Prof. Joseph Loconte about an episode early in WWII, shortly after the publication of The Hobbit. Tolkien spoke about dragons to an audience including children on the first day of 1938. He was in favor of teaching children about monsters, reasoning that they already had some idea of them and were afraid. The stories tell the other side, of heroes and of victories over monsters.
The relative lightness in tone of The Hobbit, compared to the deeper and wider dangers of The Lord of the Rings, which Tolkien began soon after, used to suggest to critics that LOTR was "about" WWII. That was easily enough shown to be false, given Tolkien's many other comments on the matter and the gradual revelation that the core story was begun during WWI. Yet it has never seemed much of a stretch that the tone of the latter work was influenced by the dark days England was going through at the time. Loconte brings out a quote I had not seen before, also from 1938 of Tolkien writing to his publisher about a possible "New Hobbit:" Tolkien confessed to his publisher that his new story was no bed-time
fable: “The darkness of the present days has had some effect on it.”