The speaker of the poem is one of several soldiers who has been marching through miserable conditions. The ground is uneven from shells and muddy from rain, yet he marches on with his company.
Soldier who dies
While the group of soldiers—the speaker and the "boys"—marches on, all are bent double and blind with fatigue. No soldiers are singled out in this march; they are one in their misery. But after the attack, one soldier is set apart in a terrible way: He is too slow to put on his protective gear and thus is exposed to the poison gas. His horrific, too-slow death dominates the imagery of the poem. To the speaker, the soldier appears to be drowning in a green sea of toxic gas. After the other soldiers get the dying man into a wagon and resume their march, he continues to suffer, his blood gurgling up from his lungs and his "white eyes writhing in his face." The poem is an argument against the idea that it is "sweet and fitting to die for one's country." This soldier's death is the main piece of evidence the speaker presents.
In the final lines of the poem the speaker addresses "my friend," saying that if this person could have experienced what he has experienced, they would not enthusiastically repeat the "old Lie" that "Dulce et decorum est / Pro patria mori," that is, "It is sweet and fitting to die for one's country." The speaker, based on experiences such as the one depicted so vividly in this poem, is convinced dying for one's country is absolutely not sweet, not fitting. An early draft of this poem was dedicated "To Jessie Pope etc." Jessie Pope (1868–1941) was a popular writer of children's poetry as well as pro-war poetry meant to encourage young men to enlist. The dedication was then replaced with "To a certain Poetess" and in later drafts left off altogether. The poem certainly provides an opposing voice to Pope and others writing similar poetry. But the progression of these dedications suggests that the identity of "my friend" expands over time to include anyone who perpetuated the lie that "Dulce et decorum est pro patria mori," including any readers inclined to believe it.
The boys in Stanza 2 are the group of World War I soldiers who are attacked with poison gas as they march. The march has been miserable—the ground is uneven from shells and muddy from rain, and they are exhausted. Yet these soldiers march on, some without their boots, limping, their feet covered in blood. They are blind and deaf with fatigue, but they keep going. The distinguishing characteristic of these soldiers is their similarity and solidarity: they "All went lame; all blind." When they are shelled with poison gas in the midst of their exhaustion, they quickly fumble to get their gas helmets on. But one soldier is not fast enough. He dies a terrible death. His death upsets the similarity of the group: before, "all went lame [and] blind"; now one is different, separate, dying. Yet at the same time the group remains intact: they do not abandon their fellow soldier, but take him along in the wagon and walk along with it.