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The Foreign Policy Essay: China’s ADIZ in the East China Sea

Eric Heginbotham
Sunday, August 24, 2014, 10:00 AM

Editor’s Note: China’s establishment last November of an Air Defense Identification Zone (ADIZ) shook many observers, who feared it was a first step in a more aggressive Chinese foreign policy. Here at the Foreign Policy Essay, we’ve already taken an early look at the issue. However, as the months have passed and a crisis has yet to emerge, analysts are beginning to take a second look at the issue. Eric Heginbotham, a senior political scientist at the RAND Corporation, contends that the reasons for China’s decision to establish the ADIZ are often misunderstood and that U.S.

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Editor’s Note: China’s establishment last November of an Air Defense Identification Zone (ADIZ) shook many observers, who feared it was a first step in a more aggressive Chinese foreign policy. Here at the Foreign Policy Essay, we’ve already taken an early look at the issue. However, as the months have passed and a crisis has yet to emerge, analysts are beginning to take a second look at the issue. Eric Heginbotham, a senior political scientist at the RAND Corporation, contends that the reasons for China’s decision to establish the ADIZ are often misunderstood and that U.S. policy needs to focus more on China’s actual behavior, not the zone itself.


Reporting on China’s Air Defense Identification Zone (ADIZ) in the East China Sea, which it rolled out in November 2013, has been highly (if understandably) skewed. (ADIZs are unilaterally declared areas that stretch beyond territorial airspace within which states impose reporting requirements on aircraft for purposes of national defense.) China’s ADIZ stretches into the East China Sea, beyond Japan’s designated “mid-point line,” towards the Ryukyu Islands, and covers the contested Senkaku Islands (known as the Diaoyu Islands in Chinese).

Global media coverage tends to be event driven, and the “event” in this case was China’s establishment of the ADIZ, which escalated an already tense situation between Japan and China. While Beijing itself did a poor job of explaining its move, its credibility would have been suspect in any case, given its assertive behavior in the South and East China Sea and the broader (if less defined) suspicion of China’s system of government. Japan, on the other hand, has a well-oiled public relations machine that has been very active on all activities undertaken by the People’s Republic of China (PRC) related to the East China Sea.

Given all this, it is little wonder that the ADIZ’s creation has been interpreted in the context of China’s expanding power and apparent ambition—and thus seen as a threatening move. No doubt, growing Chinese power has been an important driver of its actions in the East China Sea, since China is increasingly able to patrol its offshore areas. But there are other background conditions that have also shaped Chinese actions, chief among them Japanese actions within Japan’s own ADIZ and Beijing’s perception of a double standard. This essay seeks to explain Beijing’s perspective (though not to endorse its actions).

China’s ADIZ is not a challenge to international rules or precedents. It will, however, almost certainly increase the number of Chinese combat aircraft that will be patrolling and conducting intercept missions in the East China Sea, which will challenge the ability of all sides to avoid and manage crises. Rather than denying China’s right to establish an ADIZ, the United States and Japan should focus on central issues: persuading China that it must avoid dangerous intercept procedures; seeking agreement on “rules of the road” for aerial interactions; and deterring China from attempting to use the ADIZ (or any other means) to unilaterally change the status quo on the Senkaku Islands.

International Objections to China’s ADIZ Definition and Procedures

Objections have been raised against China’s ADIZ on the grounds that it covers contested land features, requires reporting by aircraft flying through the ADIZ but not towards Chinese airspace, and might be interpreted by China in ways that imply sovereignty within the ADIZ’s boundaries. Although the ADIZ does raise important issues for the United States (addressed below), early criticisms have generally been off base. Beyond the right to take measures deemed necessary for self-defense, there is no body of international law that governs the establishment of or administrative procedures for such zones.

ADIZs are unilateral measures that have been enacted by a number of states, and there is a lack of consistency in the specific provisions of different states’ practices. Many other states’ ADIZs cover areas contested by rivals: South Korea’s ADIZ covers roughly a third of North Korea’s land area (naturally claimed by Pyongyang), as well as Tokdo, a group of small islands claimed by Japan (and known as “Takeshima” in that country). Following the announcement of China’s ADIZ, which covers Ieo Island (actually a submerged rock)—claimed by both South Korea and China—the South Korean government extended its ADIZ to also cover the island. Japan’s ADIZ covers the Senkaku Islands, and although Tokyo claims there is no dispute over those islands, the Chinese certainly disagree.

The fact that an ADIZ extends into or over airspace controlled by others does not imply a claim of sovereignty. For example, Japan’s ADIZ covers Ieo Island, which Japan does not claim, but does not cover Tokdo, which it does. Nor, if it does claim sovereignty over a contested area, does it necessarily imply that patrol or intercept flights will be conducted over those areas. In fact, Chinese aircraft have not intruded into Japanese-claimed airspace around the Senkaku Islands since the Chinese ADIZ was announced, and China has given no indication that it will treat the area covered by its ADIZ as sovereign airspace.

Others have objected to China’s ADIZ on the grounds that, unlike other states’ ADIZs, it requires aircraft that will be transiting the zone but not intending to enter Chinese airspace to file flight plans with and identify themselves to China. This objection, too, appears questionable, as Japan reportedly requires Taiwanese aircraft entering its ADIZ to file flight plans regardless of destination, and rules published by Australia, the Philippines, Myanmar, and Taiwan governing activities within their ADIZ also require such reporting.

Chinese Motivations and Japan’s ADIZ

Japan’s ADIZ, originally established by the United States and inherited by Japan in 1969, is likely not China’s only motivation for establishing its own ADIZ. Beijing has denied that the ADIZ targets any particular country and has said that it simply established the ADIZ to ensure its self-defense by identifying potential aerial threats early and at a safe distance from China. And to the extent that it has expressed dissatisfaction with others’ ADIZs, Japan is not the only target: Beijing has periodically complained that the United States insists on its right to fly reconnaissance aircraft unhindered off the Chinese coast while maintaining an ADIZ around its own periphery.

However, answering Japan’s ADIZ was almost certainly an important driver of China’s decision. Although China may decide to establish an ADIZ in the South China Sea in the future, it is telling that it chose to establish the East China Sea ADIZ first—and its designated boundaries mirror Japan’s ADIZ in the East China Sea to a remarkable extent. China’s ADIZ extends to within 130 km from Kyushu, about the same distance as the closest part of Japan’s ADIZ is to the Chinese mainland. Reportedly, the area ultimately included within China’s ADIZ was expanded significantly from earlier blueprints as retaliation against Japan for its position on the Diaoyu Islands.

It is therefore worth considering the Japan-related context for China’s initiative. Japan has used its ADIZ not only to protect its airspace by identifying aircraft well before they might enter Japanese airspace, but also as an effective public relations and diplomatic tool vis-à-vis China. The Japanese Ministry of Defense (MoD) publishes detailed statistics on scrambles to intercept aircraft within its ADIZ, together with details of some of those events (such as aircraft tracks and photographs). In recent years, the Japanese MoD has highlighted a steadily increasing number of intercept missions against Chinese aircraft in Japan’s ADIZ.

These intercepts are often described by both domestic Japanese and foreign media outlets in ways that give the impression of Chinese challenges to Japanese airspace. In July 2014, for example, the Kyodo News Agency reported updated numbers of intercepts against “feared intrusions by foreign aircraft into Japanese airspace” and “incursions into Japan’s ADIZ.” Reporting on the same story, The Wall Street Journal, citing “experts,” stated that “China had stepped up its provocations against Japan in the sky over the East China Sea.” Perhaps the history of Soviet and Russian challenges to U.S., Japanese, and NATO airspace—mounted by bombers approaching airspace in mock attacks—has conditioned casual observers to expect that ADIZ interceptions would confront similar threats or that China would pursue behavior similar to that of the Soviet Union (and now Russia).

However, a more careful reading of specific intercept data included in the Japanese MoD reports paints a different picture (though it is important to emphasize that the MoD reports only document a minority of the intercept attempts—probably those that resulted in actual intercepts and photos being taken).

First, until just over a year ago, the Chinese aircraft against which Japanese fighters have been launched were not close to Japanese airspace at the time they were intercepted, nor did they appear to have any intent of approaching Japanese airspace. Rather, most of the intercepts involved Chinese aircraft patrolling along the mid-point line, just beyond a string of Chinese oil and gas platforms that parallel the line. As drawn by the Japanese side, the mid-point line is roughly equidistant between Japanese islands and China and marks Japan’s exclusive economic zone (EEZ) claim. Hence, most of these aircraft were flying tracks parallel to the Ryukyu Islands at a distance of roughly 150 nm (277 km) from Okinawa Island—well beyond the 12 nm (22 km) airspace limit. Second, again until the last year or so, most of the Chinese aircraft targeted appear to have been intelligence, surveillance, and reconnaissance (ISR) assets—primarily slow-moving, propeller-driven aircraft, many from civil administrative bodies.

Hence, Japan’s ADIZ was likely doubly galling to Beijing, as Japanese intercepts within it were likely viewed as harassment of aircraft flying deep within international airspace that enabled Tokyo to paint a picture for the global media of Chinese provocation and a challenge to Japanese airspace. Until very recently, the preponderance of fighter aircraft operating at any distance from shore in the East China Sea appear to have been Japanese. Chinese media has complained for years about this treatment, and it should have come as no surprise that Beijing would want to answer Japan’s ADIZ with one of its own.

Increased Chinese Aerial Activity in the East China Sea

Although China has been steadily modernizing its air forces and other parts of its military for more than three decades and rapidly increasing its defense budget for the last two, many of those efforts are only now coming to fruition. China has, until the last several years, had limited capability to patrol even those areas immediately offshore, and it still has weaknesses in several support functions necessary to project force. Recent increased Chinese air activity off its coast, and over the East China Sea in particular, represents a natural outgrowth of its maturing air capabilities.

Japanese MoD data presents the number of intercepts attempted, rather than incursions into Japan’s ADIZ per se. But assuming that intercept attempts track proportionally with the number of entries into Japan’s ADIZ, Chinese activity appears to have increased dramatically over the last several years, with the number of Japanese intercept attempts against Chinese aircraft having risen from 38 in FY 2009 to 415 in FY 2013 (ending in April 2014).

In terms of the types of activities observed, there have been a number of firsts in the last few years. On December 13, 2012, a Y-12 (twin-engine, propeller-driven surveillance aircraft) belonging to the Chinese State Oceanic Administration made the first ever unauthorized Chinese intrusion into Japanese-claimed airspace, flying near the Senkaku Islands. (Between 1967 and the end of 2013, Japanese airspace was illegally entered 37 times, once each by Taiwan and China and 35 times by the Soviet Union and its Russian successor.) It is difficult to evaluate the significance of this event, since it has not been repeated since.

However, other new activities have been repeated: in July 2013, a People’s Liberation Army (PLA) Y-8 surveillance aircraft flew through the East China Sea, through the Miyako Strait, and into the Western Pacific—marking the first time that a Chinese military aircraft had flown through the Ryukyu Islands to the Pacific. In September 2013, two Chinese H-6 bombers took the same path to the Western Pacific, as did mixed groups of three to four H-6 bombers and Y-8 surveillance aircraft on four subsequent occasions through the end of April 2014 (the last Japanese reporting date). Because the Miyako Strait is 300 km wide, Chinese aircraft do not have to traverse Japanese airspace; however, these operations show the Chinese military’s increasing reach.

Of greater relevance to the ADIZ are China’s intercept activities, though it should be noted that these predate the establishment of the ADIZ itself. In January 2013, Chinese J-7 and J-10 fighters reportedly tailed U.S. P-3C and C-130s over the mid-point line in the East China Sea. Another incident, also in January 2013, saw the first reported episode involving fighters from both Japan and China. In the incident, a Chinese Y-8 surveillance aircraft was intercepted by two Japanese F-15s, and China responded to Japan’s intercept with two J-10 fighters of its own.

The nearest Chinese airbases to the contested areas of the East China Sea originally held third-generation J-7 fighters, but modern J-10s have been deployed over the last several years. Since the ADIZ was declared in November 2013, China has begun using longer-range and more capable twin-engine J-11s in East China Sea intercepts. At least some of these have been from bases in Chongqing, some 1,500 km distant, suggesting that they staged from forward bases in Fujian before flying missions and indicating a considerable degree of operational flexibility.

The number, range, and sophistication of Chinese intercepts will likely increase further as China adds improved Airborne Warning and Control System (AWACS) and other support capabilities (especially aerial refueling and new bases closer to operational areas). Establishing the ADIZ was not necessary for increased patrol activity, but will provide a framework and coherence for such activity. It is conceivable that within the next 10 years, Chinese intercept activity in the area could reach the same level of operational intensity as Japan’s. And as both sides improve their ability to react quickly to rapidly evolving aerial situations, the frequency with which fast-moving fighters will be in contact with one another could increase dramatically.

Focus on Activities

Rather than responding to the ADIZ itself, Washington should focus on Chinese behavior in the East China Sea. The challenge of both deterring China and avoiding crises (or crisis escalation) in the East China Sea will likely grow over time, and the task of deterrence may at times conflict with efforts to discourage Japan from taking actions that could exacerbate tensions and make crises more likely.

Japanese officials have complained about dangerous Chinese intercepts, citing an incident in May 2014 in which a Chinese military aircraft closed to within 30 meters of a Japanese aircraft. Here, too, customs differ: while Japan limits the intercept distances of its own intercepts, the United States gives greater leeway to pilots in evaluating safety. Chinese pilots, however, do not have the experience and likely lack the training to make judgments with the same degree of proficiency. The United States and Japan will therefore want to engage China on air intercept procedures.

The United States and China already discuss aerial interactions as part of the Military Maritime Consultative Agreement (MMCA) but have made little progress since the talks were established in 1998. Given the prospects for dramatically increased aerial contact in the East China Sea, every effort should be made to reenergize these talks, and perhaps elevate their status.

Japan and China should also be encouraged to implement agreements reached during the inaugural meeting of the “Japan-China High-Level Consultation on Maritime Affairs” in May 2012, especially the agreement on establishing a hotline and other crisis communications, and to restart the talks as soon as possible. In the meantime, aircraft video taken from Japanese and U.S. military aircraft and other evidence of unsafe activities may be useful in pressuring the PLA to enforce safe (or safer) intercept practices.

Most important will be maintaining a consistent position with regard to the East China Sea and making it clear that the United States is committed to opposing unilateral changes to the status of the Senkaku Islands (or any other areas). In this effort, a focus on the permissibility of the ADIZ is a distraction. China has as much right to establish such a zone as any other state. But the United States should carefully monitor where and how Chinese aircraft fly, and it should encourage China to avoid dangerous intercept procedures while advocating for the development of “rules of the road” for aerial interactions. Otherwise, the United States will wind up wasting time fighting a legal battle it cannot win, instead of addressing pressing issues that more directly engage the U.S. national interest and prospects for war and peace.

Eric Heginbotham is a principal research scientist at the MIT Center for International Studies and is co-director of the Wargaming Lab at the MIT Security Studies Center.

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