The irony in the poem is foreshadowed by the irony in this title. Owen writes a bitter poem about the fate of so many soldiers in World War I and deliberately uses the title to mock the expectations of what his readers can expect. An anthem is a word used to describe a religious song or a song of national joy and pride as in the national anthem. Here of course the usage is very different, as the song is not about joy and pride in any way. This is indicated by the end of the title which refers to "doomed youth." Normally, the "youth" are viewed as being full of hope and possibility for the future. The fact that the title declares they are "doomed" clearly indicates that Owen is writing some kind of song lamenting the fate of the youth he writes about. This is indicated in the very first few lines of the poem:
What passing-bellsfor these who die as cattle?
Only the monstrous anger of the guns.
Only the stuttering rifles' rapid rattle
Can patter out their hasty orisons.
Owen turns his poem into a mockery of a religious funeral service, where the soldiers are compared to "cattle" in the way that they are being almost led mindlessly to slaughter and the alliteration and onomatopoeia in "rifles' rapid rattle" is used to convey the prayers that accompany the deaths of the "doomed youth" that die so mindlessly and without sense or purpose. The title therefore draws attention to the sarcastic, bitter tone of the poem as Owen writes about the "doomed youth" of whom he is a member.