AP Photo

Many citizens of China, the Philippines and Vietnam won’t have heard of the tiny scraps of land in the South China Sea that their governments compete with one another to claim. Certainly, almost none will ever set eyes on them.

So are places like Scarborough Shoal, the scene of Beijing and Manila’s latest maritime spat this month, really worth all the aggravation? And whose fault is it that these confrontations, which have the potential to start wars – and at the very least to kill fishermen and sailors – keep on happening?

Tiny, uninhabitable islets like Scarborough Shoal have little value per se, but the resources that surround them have plenty. The islets serve as pins in a map, around which governments can draw dotted lines and claim...