Wall

You may ask: There’s an important military construction in the ancient China – we have the Great Wall!

Very true, but the consideration is different.

You see? Although it was not prohibitively expensive to keep a large army at the border, and maintaining the Wall is often a nuisance, but, for the emperor, an large army far away is more risky.


Just think about the stories of An Lushan (安祿山), Zhu Di (朱棣), and, alas, many others.

PS. In that sense, the entire country becomes a gigantic castle surrounded by the Wall.

All of a sudden, I find that novel of Franz Kafka has an entirely different meaning.