This famous poem was written about the experiences of its author during World War I and how, in particular, the poet's wartime experience caused him to question and to challenge outright many of the assumptions that people had at home concerning war and how noble and wonderful it was. The title of the poem immediately shows this emphasis, as it is the initial part of a Latin quote that means "It is sweet and fitting to die for one's country." Note how Owen creates a dramatic contrast between this title and the opening of the poem, which is worthy of some attention:
Bent double, like old beggars under sacks,
Knock-kneed, coughling like hags, we cursed through sludge,
Till on the haunting flares we turned our backs
And toward our distant rest began to trudge.
We have in our mind an impression of what soldiers should look like, dressed smartly in their uniforms and bravely marching together towards battle to perform their heroic exploits. Owen, by contrast, presents us with a band of exhausted soldiers going away from the front line, retreating, who have been completely dehumanised by their experience of war. They are described as "beggars under sacks" and "coughing like hags." There is no sense of bravery or heroism in their figures at all.
The episode of someone being gassed and the horrific visual way in which we are allowed to see his "white eyes writing in his face" and hear the sounds of his "froth-corrupted lungs" conveys the true horror of this war. This soldier did not meet his death engaging the enemy. He is killed by an accident without seeing an opponent, and dies a gruesome death. The change of person in the poem augments the power of Owen's argument, as he moves from third person to first person and then finally addresses the reader:
If in some smothering dreams you too could pace
Behind the wagon that we flung him in...
My friend, you would not tell with such high zest
To children ardent for some desperate glory,
The old Lie: Dulce et decorum est
Pro patria mori.
Above all, this change of person forces us to become involved in the action of the poem and makes us question to what extent our attitudes of war reflect "the old Lie" and how our impressions may impact "children ardent for some desperate glory." This poem therefore represents a plea to understand the true horror of war.