Screwtape has received a deliriously joyful letter from Wormwood. The European humans have started another war. The patient has been sleepless with anxiety. Screwtape acknowledges the headiness of war, with all its potential "anguish and bewilderment of a human soul." He cautions Wormwood not to lose sight of this chance to secure his patient's soul. Terror for the future and the horror that is coming are tools for "undermining faith and preventing the formation of virtues." However, the patient's reaction to the war must be carefully assessed before action is taken. Wormwood can then determine if is best to move the patient toward becoming "an extreme patriot or an ardent pacifist."

While war, from Screwtape's standpoint, is entertaining, he warns Wormwood not to expect too much from it. There may be suffering, but it is short and may be endured by humans who are already in the Enemy's camp. This does not satisfy the devil's hunger for souls. What they must consider is how to use war to their advantage.

Despite war's hoped-for "cruelty and unchastity," there is the danger that its tribulations will turn humans to the Enemy by the thousands. Even more may turn their attention to moral values and virtuous causes. Worse, some may go willingly to death knowing they are "of the Enemy's party." It is better, Screwtape notes, that humans die of old age, in nursing homes, surrounded by doctors and nurses who will lie to them about their failing condition. Out of misdirected compassion, they will be denied access to a priest in order to shield them from that truth. Screwtape concludes that the constant reminders of death that accompany war render useless the devil's best weapon: contented worldliness and the denial of mortality.