Aside from national pride, ownership could give Japan or China control of oil and gas resources.
For most of human history, the five rocky islets in the eye of the current diplomatic storm between China and Japan have sat in remote and irrelevant obscurity, lapped by the tropical waters of the East China Sea.
But for generations of humbler folk on both sides, the islands have meant one thing: fish. The Chinese name for the island group, Diaoyu, means "catch fish." The Japanese name for the largest island, Uotsuri, means "fish catch."
There may be oil and gas in nearby waters, according to some surveys, making ownership of the islands – and their adjacent exclusive economic zone – even more attractive.
But all the tiny islands themselves have ever been good for is albatross feathers (for the fashion trade) and a Japanese-owned fish-processing plant that operated for the first 40 years of the past century.
Japan bases its claim to the islands, which it calls the Senkaku, on a cabinet decision in January 1895 whereby because there was no trace of anyone else controlling them they were deemed "terra nullius," nobody else's, and Tokyo incorporated them into its territory.
China disputes that claim, pointing to 15th-century accounts of sea voyages by Chinese envoys and a 17th-century map of China's sea defenses, among other documents, to show that "the Diaoyu islands were first discovered, named, and exploited by the Chinese," in the words of a Foreign Ministry statement.