The tone shifts in Stephen Crane's "War is Kind" come as a result of the change in diction. For instance, in stanza two rather than use the conversational tone of the other stanzas, Crane chooses to employ more elevated and Romantic language in the second stanza. This embellished and exaggerated style--
Great is the battle god, great and his kingdom
A field where a thousand corpses lie.
is employed by Crane to show how absurd it is to glorify wars and attach Romantic ideas to them. For, the contrast between the field with a thousand corpses lying promiscuously about in crumbled forms, is much less heroic than any deeds of glory. In a switch from the second stanza and its apparent cynicism and mockery, Crane exhibits an ironic sympathy to the victims and their mothers:
Mother whose heart hung humble as a button
On the bright splendid shroud of your son,
Do not weep.
War is kind.
There is some comfort in knowing that the victims of war have found respite from their suffering.