Japan and South Korea’s willingness to back an Australian-led statement accusing China of cyberspying signals the emergence of a new de facto alliance fed up with Beijing’s relentless campaign of intrusions in government and private sector networks.

The two countries have been reluctant to call out China’s cyberespionage, but months of diplomatic work and discussions among security agencies and technical experts led to Tokyo and Seoul adding their voice – a welcome surprise to officials involved in the behind-the-scenes work.