Air defence identification zones (ADIZs)—in the news following the recent declaration of China’s first such zone covering the disputed Senkaku/Daioyu islands in the East China Sea—are an international anomaly. They are neither allowed by any international treaty nor are they prohibited under international law. Consequently, they are not governed by any international organization and any country can unilaterally demarcate and police such zones.

Yet, as per established ADIZ norms, civilian aircraft traversing such zones are expected to submit flight plans to the country enforcing the zone. However, this does not normally include military aircraft. Countries that draw this contemporary lakshman rekha are expected to have the ability to detect, identify and, if necessary, defend against unauthorized aircraft movement in their zones.

The US was the first country to demarcate such a zone at the end of World War II and China is merely the latest country to do so. Several others, including almost all of China’s neighbours—India, Japan, South Korea, Taiwan and Vietnam—have also established similar zones.

China’s decision and timing of declaring its zone deftly exploits this international anomaly. It is also a tacit declaration that China has now acquired the ability to detect, identify and take action against aircraft well beyond its territory.

There are, however, a couple of key differences between China’s ADIZ and earlier ones. First, almost all of ADIZs until now have been established over undisputed areas and were created to defend the status quo and the country’s territory. China’s ADIZ over the disputed Senkaku/Daioyu islands is, clearly, designed to challenge the status quo rather than protect its sovereign territory. Second, contrary to existing norm, China has demanded that both civilian and military aircraft submit their flight paths if they are crossing its ADIZ. In response, the US asked its civilian airlines to submit plans, but defied Beijing by flying its biggest and least stealthy military aircraft without notification. Predictably in his visit to Beijing, US vice-president Joe Biden criticized the abnormal reporting requirements, the timing and the area covered by China’s ADIZ, but not the principle of such a zone; doing so would bring into question the legitimacy of every other ADIZ. He also did not relent on the right of the US to send military aircraft though the zone without notification.

For India, which drew its own aerial lakshman rekhas along its borders much earlier though it did not have the ability to effectively detect, identify or defend against unauthorized aircraft (apparent from the spate of incidents over the years of aircraft flying undetected through India’s zones), China’s zone poses two challenges. First, it highlights that despite India’s improved detection capability today (through the Phalcon AWACS and balloon-based Aerostat radar), it still lags way behind China’s apparently superior and ever improving early detection ability. New Delhi needs to address this lacuna and enhance its detection, identification and defensive capability, particularly in the areas bordering China, as a matter of urgency.

Second, China’s imposition of an ADIZ over a disputed area might encourage it to impose a similar zone over Arunachal Pradesh (which Beijing considers disputed territory) or challenge India’s ADIZ, which extends till the line of actual control. While Beijing has sought to assure New Delhi that it will not do so, there is no guarantee that this decision is irreversible.

In the short term, India should bind China to its assurance through a formal agreement. Here, how the unfolding East China Sea issue is resolved would be of relevance. More importantly, in the medium term, India needs to resolve the border dispute and clearly demarcate the boundaries with China. Otherwise, this crucial lakshman rekha will be rendered defenceless.

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