Barrett created two works inspired by Sassoon's 1918 poem Attack. In these works he shows the horror of war as a mechanisation of soul and nature. The increasing prevalence of tanks on the battlefield from 1916 onwards was paralleled during the First World War with the increasing battle-hardness of the soldiers.
In his poem Sassoon records the preparations preceding an attack by the British Army on the Western Front. A deeply charged poem, Attack stands in contrast to Sassoon's more reflective poems where the hardness of actual battle is foreshadowed rather than recounted directly.