Wilfred Owen wrote poems that are astringent rather than sentimental. His poem "Dulce et Decorum Est"—a title taken from the last two lines from Horace, Odes III:ii: "Sweet and fitting it is to die for the fatherland"—sharply contradicts this idea. By using oxymorons, Owen aims to shock people out of their illusions that war is a noble venture. The astringency of these contradictions presented with the oxymorons in the poem removes the sentimentality from the idea of war.
In order to convey the perversity of the idea of the glory of war, Owen employs oxymorons, figures of speech in which two successive words collide to create rhetorical effects as they contradict each other. One such oxymoron is "smothering dream." The contradiction between the negative connotation of the word "smothering" with the pleasant connotation of "dream," has an impact that produces the realization that the mustard gas chokes off all dreams of a future for the soldier. Another oxymoron is "desperate glory" since these two words have contradictory denotations. For, a desperate person is in a negative state, but glory involves positive feelings. Certainly, there is no glory—no achievement—in desperation, or death.