“A heretic may see the truth and seek redemption. He may be forgiven his past and be absolved in death. A Traitor can never be forgiven. A Traitor can never find peace in this world or the next. There is nothing as wretched or as hated in all the world as a Traitor.”— Anonymous Inquisitor
Secessionists sometimes fall prey to the promises of alien empires or, worse still, the dark powers of the Warp. No mercy can be shown to such traitors. Only ignominious death can reward those who follow such vile masters.
The influence of the Warp presents an especially great peril to the Imperium and humanity. Its malign entities and shadowy gods always look for a way to break free of their otherworldly realm and wreak havoc upon reality. Such was the terrible fate of Horus so long ago when he turned upon the Emperor and, since that time, the daemons and the Dark Gods of Chaos have twisted countless others.
For the Imperial Guard, to fight such foes presents the most perilous kind of war, a war in which even the victors can find defeat if they themselves acquire a taint while facing their foes. Many times, regiments win great victories against the powers of the Warp and their thralls, only to be put to death themselves for fear that they acquired the taint of Chaos and if left alive would turn against the Imperium they once swore to protect.