In 1917, Owen was sent to Craiglockhart War Hospital for shell shock (what would now be called posttraumatic stress disorder, or PTSD). There Owen encountered the poet Siegfried Sassoon. While they were both recuperating at the hospital, Owen often shared his poems with Sassoon, who was seven years Owen's senior. As a fellow soldier and poet, Sassoon became a friend and mentor figure to Owen, offering revisions of Owen's work and deeply influencing his poetic style.
"The Next War," written while Owen was at Craiglockhart, features the last two lines of Sassoon's poem, "A Letter Home," as an epigraph. Sassoon's poem, addressed to his friend and fellow poet Robert Graves, memorializes the death of a mutual friend who was killed in action. As the poem progresses, "A Letter Home" imagines their mutual friend's rebirth as a mythical figure.
"A Letter Home" has an irreverent attitude toward war. As the second to last line declares, war is "a joke" for Sassoon and Graves as they know their dreams of rebirth and regeneration will triumph over the darkness of war.
"The Next War" begins by borrowing this irreverent attitude toward war, specifically toward death. However, "A Letter Home" ends on a much more hopeful tone. Nevertheless, "A Letter Home" clearly influences "The Next War" in matters of tone and content. Both poems, ultimately, acknowledge the terrible loses of life that war brings about.