Sabre-rattling between governments is dangerous at the best of times, but when it encourages citizens to take matters into their own hands, the situation becomes potentially explosive. A row between Japan and China over control of a deserted chain of islands in the South China Sea, has sparked expeditions by protesters from both countries.

In the latest incident, Japanese activists landed on the Island waving their national flag, resulting in counter-protests in several Chinese cities and a diplomatic rebuke from Beijing. Japan — correctly — is trying to play down the incident to avoid a potentially costly diplomatic and economic spat with China.

The ownership of the islands is distorted and disputed by war and history. Taiwan has also laid claim to them. On their own, there is little besides a dangerous brand of nationalism to justify the depth of the dispute about the islands. But, the islands may well lie on or close to significant reserves of oil and gas, which can provide a vital boost to the economies and energy security of the competing nations.

Nationalism and economic interests are a dangerous mix, especially in a region where memories of the last war are still raw. No matter what their domestic political agendas are, the governments of China and Japan must cool national emotions and send the dispute for international arbitration and a permanent settlement. Anything else is simply too risky in a tense region of the world.