China has accused Japan of ‘reckless militarism’. What’s behind the latest tensions?

Relations between Tokyo and Beijing have ebbed and flowed in the decades since the second world war, but hit an undeniable low this week.

Denouncing what it proclaimed was Japan’s “reckless pursuit of ‘new militarism’”, this week China imposed new export controls on 40 Japanese companies over dual-use items, or items that can be used for both civilian and military purposes.

The move came as Tokyo protested against joint exercises by Chinese and Russian bombers near its airspace, and claims that the Chinese coast guard had entered its Exclusive Economic Zone. Japan also announced it was deploying missiles launchers on its easternmost island.

What has sparked the tit-for-tat tensions, and is an off-ramp likely?