How does Guenter Grass's novel "The Tin Drum" deal with politics of the second world war?

Guenter Grass's 1959 masterpiece The Tin Drum follows Oskar Matzerath, a boy who lives in Poland through World War II. Grass places Oskar in the midst of several historical political events, such as the German invasion of Poland (during which the lover of Oskar's mother is assassinated).
The Tin Drum deals heavily with the atrocities of war, the horrors of adulthood, and the moral deafness carried out by Germans during preceding and during the rise of Nazism in Europe. The protagonist Oskar makes a choice to stop growing and maintains the infantile appearance of a three-year-old. The titular tin drum, which Oskar is seemingly obsessed with, symbolizes a fight against the denial and moral compromise of the German people. Oskar's decision to remain childlike—and, thus, exempt from the guilt of adulthood—mirrors the compliance of countrymen during the rise of Nazism.
It is often suggested that Guenter Grass's intention in writing The Tin Drum was to remind the German people of the horrors of war during a time that much of the atrocities were hoping to be forgotten.