What is a critical analysis of the poem "O What is That Sound"?

W.H. Auden’s “O What is That Sound” is a ballad in which two narrators—presumably married—converse about a troupe of soldiers that is coming toward their home. The poem was published in the early 1930s, a time of growing civil unrest and military strategizing as Europe marched ever closer toward World War II.
Each stanza follows a question-and-answer format with an ABAB rhyme scheme throughout. The first line of each stanza begins with “O,” which indicates a sense of urgency or confusion. The repetition in the poem emphasizes this tone and establishes a sing-song rhythm that mimics the “drumming, drumming” mentioned in the first stanza.
A shift occurs at the end of the seventh stanza with the line “And now they are running.” While earlier descriptions of the “scarlet soldiers” have been rather rational and unconcerned, the second narrator, who has been answering the other’s questions, seems surprised by this detail. Noticing for the first time that the soldiers seem headed directly for their home, the second narrator is distressed.
The last two stanzas of the poem have a frightened, suspenseful tone that suggests something violent is about to happen to the narrators: the soldiers’ “boots are heavy on the floor” and “eyes are burning.” The imagery of burning eyes suggests anger or destruction, which is directed toward at least one of the narrators.
Therefore, Auden is commenting on the destructive, violent nature of war that invades even the most provincial places—along with the persecution it includes. Considering that WWI had ended shortly before the poem’s publication and that WWII came shortly after (Hitler became chancellor of Germany in 1933), Auden’s poem has an almost prophetic mood.