The speaker of this poem is a young man of rural lower-class origins who enlisted as an infantryman and who has just killed an enemy soldier (“my foe”) in battle. The symmetry of the situation strikes and puzzles him and he tries unsuccessfully to work out why he should have killed the other, since in every way they are fellow men.
The poem is in ballad form: stanzas of four lines rhyming ABAB, in iambic trimeter except for the third line which is iambic tetrameter. The ballad form is traditionally used for tragic, comic, and heroic tales in plain language, appropriately for this soldier’s story, which is all three.
The poem conveys the speaker’s background through small touches of vocabulary: the dialect term “nipperkin” for a small drinking-glass; the abbreviation “’list” for “enlist”; and the use of “like” instead of “likely”. The phrase “old ancient inn” in the second line would be an unacceptable pleonasm in the usual elevated language of poetry, but in the speaker’s plain language, we understand “old” as meaning “ordinary, commonplace, usual”. In the third stanza, the speaker imagines that the dead foe might have “sold his traps” (that is, he had been a poacher, but in destitution had sold his only means of living, forcing him to join the army to avoid starvation), an idea that suggests the speaker himself had been familiar with poaching. In the last stanza, the speaker rhymes “war is” with “bar is”, which locates his accent, via the card–cord merger, in the West Country of England.
The speaker has difficulty understanding the reason he killed his foe. This difficulty comes to a head in the third and fourth stanzas. He hesitates, repeating the word “because” and the phrase “my foe”; he tries to convince himself by saying “That’s clear enough” even though it is far from clear; his syntax becomes fractured, with incomplete phrases linked by dashes; and most strikingly, there is an enjambment after “although” that spans the two stanzas, breaking the normal rule of ballad form that each verse should end on a stop. These are all indications of the speaker’s inability to make sense of the situation.
The symmetry between the speaker and his foe is suggested throughout. They found themselves “staring face to face” like a man looking at himself in a mirror. In two places a phrase is repeated but with the elements in mirrored order (a chiasmus): “I shot at him as he at me” in the second stanza and “he was my foe … my foe of course he was” in the central lines of the the third (central) stanza. In the fourth stanza, the speaker guesses that his foe had enlisted for the same or similar reason (“just as I”), emphasizing the similarity of their social positions. In the last stanza, the pronoun has changed from “I” to “you”, suggesting that the speaker and his foe have swapped places.
The whole structure of the poem is symmetrical: the first and fifth stanzas both describe how he would have shared a drink (“wet many a nipperkin” / “met where any bar is”), or even his pay (“help to half-a-crown”) with the foe, had they met under happier circumstances. The second and fourth stanzas both describe how they came to face each other: through enlisting in the fourth stanza, and through being “ranged as infantry” (lined up in battle) in the second. And the third stanza sets out the central unsolved conundrum: why did the speaker kill his foe and not the other way around? A question for which he can supply no adequate answer.