Tension between Japan and China has escalated over the new Japanese leader's suggestion Tokyo could intervene militarily if Beijing attacks Taiwan.

China and Japan are two of Asia’s most powerful nations and the region’s biggest trading partners. Yet centuries of intense rivalry mean their economic embrace can never be taken for granted.

Beijing is flexing its military and economic might to show its displeasure with the Japanese leader’s comments about defending Taiwan. But its aggressive approach risks backfiring.

If Japan’s hawkish new prime minister, Takaichi Sanae, has her way, Japan’s security evolution will quicken. The country’s military build-up is a response to increasingly aggressive neighbours in China and North Korea and to an ever more unreliable ally in America.

Residents in the northern region of Akita are living in fear after dozens of assaults on humans. Riot police and the army have been sent to help.