In The Hour of Decision, Oswald Spengler portrays a brutally critical image of modern Western civilization. According to Spengler, the West is destined for decay and heading towards its demise, poisoned by excessive rationalism, a lack of functioning hierarchies, and widespread alienation. Spengler's observations are rooted in Germany during the interwar period, a time characterized by political unrest and economic chaos.

It was clear to Spengler that the world, following the imminent international showdown, would hardly be recognizable. He regarded our era as the most fateful and serious in human history, a phase in which the destiny of peoples and nations would be determined.

The Hour of Decision ("Jahre der Entscheidung") quickly became a commercial success when it was published in Germany in 1933. However, it was later banned because Spengler criticized Nazi politics in various ways, including a rejection of their racial-biological foundations.