The Huns also knew that they were not adept at siege warfare, so they began to play to their strengths and avoid their weaknesses. They would only head south to raid, snatching what they could before retreating, rarely engaging with fortified cities or strategic passes. The Han army was forced to follow their lead, eventually leaving them with no choice but to begin constructing the Great Wall. However, there is no logic in playing the role of a thief for a thousand days, let alone defending against one for a thousand days. Constant defense inevitably leads to failure, and border passes were still breached from time to time, resulting in heavy losses.
"But the Han Dynasty did not just sit idle; they began to study their opponent’s strengths and seek ways to counter them."
"As I mentioned before, agrarian societies are characterized by the simultaneous advancement of all trades."
Chapter 62