In just a few lines, the speaker moves from a dull office routine to a startling confession. He goes to work, where his job is to give advice about hanging the poor. He mentions this flatly, as if it were ordinary paperwork. Then comes the turn: he misses the army.
What he misses is disturbing. He lists robbing, spreading fear, and "breaking the world." Soldiering, in his memory, was about open violence. Civilian life has only made that violence quieter and more official, since he now helps harm people through advice instead of force.
The speaker seems restless and bitter, but not guilty. He sounds nostalgic for cruelty. The title, "Civilian," becomes ironic, because the word suggests peace, yet nothing in his life seems peaceful or decent. The mood is cold and unsettling. The short, clipped lines make it feel blunt and matter-of-fact, which is what makes it chilling. The poem seems to suggest, judging by its tone, that the machinery of harm continues in ordinary offices, just in a more respectable form.