What is the main theme of poem lights out?

The main theme of the poem 'Lights Out' by Rudyard Kipling is the harsh realities of war and the sacrifice of soldiers. The poem reflects on the soldiers' experiences during the First World War and their daily struggles. It highlights the soldiers' exhaustion, fear, and despair as they face the nightly routine of turning off the lights in the dugouts, signaling the end of another day of fighting. The phrase 'Lights Out' suggests the extinguishing of hope and the arrival of darkness, both literally and metaphorically. The poem serves as a poignant reminder of the personal toll war takes on those who fight in it.