Two debates are under way over China. The first, about Beijing’s aggression in the South and East China seas, is between naval strategists and diplomats who know little about economics. The second, about the fragility of the Chinese economy, is between economists who know little about naval strategy and diplomacy.

These debates should intersect but they rarely do. In one, China appears invincible; in the other, it seems to be on the brink of implosion.

The background to the first debate is China’s seemingly inexorable military expansion, especially in sea, air, ballistic missiles and cyber warfare. As regards sea forces, this includes not only warships but also coastguard vessels, merchant shipping and strategic deployment of oil rigs. Beijing’s ability to co-ordinate all these attributes of power has resulted in a subtly shifting military balance in maritime Asia.