AP Photo

A third of world trade passes from the Indian Ocean via the Malacca Straits into the South China Sea, including the oil needed to power East Asia's economies. Japan imports 90 per cent of its oil, China about 50 per cent and rising. The remnant of a prehistoric continent, the shallow Sunda Shelf, means that conditions are optimal for offshore oil and gas exploration. About 10 per cent of the world's fishing catch is derived from the South China Sea, much of it caught by Vietnamese boats that sell to China's teeming coastal populations. Any number of fishermen have been detained by the coastguards of several littoral nations.