The primary motif in the poem is the phrase "war is kind." The fact that it appears in the title, as well as numerous times in the poem, suggests its significance. It is through this motif that Crane develops the tone of the poem, one of verbal irony. The idea that war is kind is sharply contrasted by several specific scenes of death and suffering. Ironically, the only way war can be "kind" is that it brings death which ends suffering--except for one powerful exception with which the poem concludes in a somber and most terribly ironic tone:
Mother whose heart hung humble as a button
On the bright splendid shroud of your son,
Do not weep.
War is kind.
Her soldier son's suffering is over, but his mother's has only begun. In terms of symbolism, there is not a single central symbol that unifies the poem. However, the "battle-god" and "his kingdom" symbolize war's violence and destruction.
In addition to the "war is kind" motif, there are other specific lines that are repeated in the poem. "Do not weep" always precedes "war is kind." Also repeated are the lines "A field where a thousand corpses lie" and "These men were born to drill and die."