Who it’s for
Christian structures the human history of the region around two primary ecological adaptations:
The greatest conceptual leap Christian offers is the rejection of the standard "Russia vs. the Steppe" dichotomy. Instead, he divides the continent into two ecological and historical zones:
The rise of the Xiongnu confederation in modern Mongolia (c. 200 BCE) is a turning point. Christian uses the Xiongnu to introduce a recurring theme: state formation via external threat. To face the Han Dynasty, the Xiongnu created a centralized military apparatus. That apparatus, in turn, pushed other tribes westward, creating the domino effect that eventually sent the Huns crashing into Roman Europe. Christian is careful to note that the "Huns" of Attila were a product of both Inner Eurasian dynamics and Roman collapse.