Annotate "Dulce et Decorum est"?

Dulce et Decorum est pro patria mori translated means it is sweet and honorable to die for one's fatherland. I have to guess that the poem you entered is by Wilfred Owen and you have to understand who he is to understand the poem. Owen and and his good friend, Son, were WWI veterans both were hit in the face with Post Traumatic Stress Disorder (PTSD). Robert Graves was another English poet and author who had similar experiences.