It’s now been a year since China unilaterally declared an air defense identification zone (ADIZ) over a large swathe of the East China Sea. Beijing’s decision to do so came at a time of rising tensions between China and Japan over the disputed Senkaku/Diaoyu Islands. While that dispute persists today, tensions were significantly higher a year ago, with the potential for escalation high on both sides. At the time, The Diplomat hosted a wide range of perspectives on why Beijing chose to act as it did and the ramifications the ADIZ decision would carry going forward for the security of the Asia-Pacific region, China-Japan relations, and more. A year later, most of the questions raised then still endure. For example, will Beijing follow up on the mixed signals it’s been sending about a potential ADIZ over the South China Sea? Could Beijing’s enforcement of its ADIZ draw international legal action? Finally, will Beijing’s justification of the ADIZ evolve with time? I’ll mostly focus on the first question here.
We’ve seen mixed signals come out of China regarding the possibility of a South China ADIZ. For example, while a senior PLA official called for China to establish an ADIZ over the South China Sea, noting that it was “necessary for China’s long-term national interest,” these calls had been contradicted by official Chinese foreign ministry statements noting that there were no plans to install an ADIZ over the South China Sea. The geography of the South China Sea and China’s capacious territorial claim to almost the entirety of the region, down to the Borneo coastline, make the decision to declare an ADIZ there more complicated. Specifically, as I’ve discussed here before, the nature of China’s dashed line claim leaves some interesting and strategically advantageous ambiguities that would be threatened with the declaration of a de jure ADIZ.