Smart Q&A: Gu Min-kyo - China's ADIZ Declaration and Korea ①: From the Perspective of International Norms

YouTube Link: video.eai.or.kr/131210_Sqa.flv

Professor Gu Min-kyo holds a Ph.D. in Political Science from the University of California, Berkeley, and is currently an associate professor at the Graduate School of Public Administration, Seoul National University.

The United States, Japan, and South Korea have all protested China's declaration of an Air Defense Identification Zone (ADIZ) on November 23. The visit of U.S. Vice President Joseph Biden to Japan, China, and South Korea from December 2-7 further clarified the opposition of the three countries, while China reiterated that its actions were lawful under international law, sharpening the differences in positions among the involved parties. Meanwhile, on December 8, the South Korean government announced the expansion of the Korea Air Defense Identification Zone (KADIZ) to include airspace south of Marado and Hongdo islands, as well as the waters above Ieodo. The airspace around Ieodo now overlaps with the ADIZs of China, Japan, and South Korea, raising concerns about increased regional instability regarding its operation. In response, the East Asia Institute invited Professor Gu Min-kyo of the Graduate School of Public Administration, Seoul National University, for an interview on December 10 to discuss how the conflicts among Northeast Asian countries over ADIZs can be understood from the perspective of international norms, and what follow-up measures South Korea should prepare. The main points are as follows:

The Meaning of Air Defense Identification Zones in the Context of International Norms

“An ADIZ is an aerial zone established outside of a country's airspace, in its Exclusive Economic Zone (EEZ) or over the high seas, to defend its airspace.”

“Since ADIZs are unilaterally declared based on the right to self-defense under international law, there are no norms that can justify them, nor norms that can prohibit them.”

An Air Defense Identification Zone (ADIZ) is an aerial zone established outside of a country's airspace, in its Exclusive Economic Zone (EEZ) or over the high seas, to defend its airspace. As it is not sovereign airspace, freedom of navigation is guaranteed. However, it is a zone where, if a threat to national security is perceived, the country may request aircraft to withdraw or even shoot them down, as previously announced to the international community. All aircraft flying within an ADIZ are required to submit flight plans and report their positions, adhering to established procedures. As of 2013, over 20 countries have established ADIZs, while Russia and North Korea, among others, do not recognize them.

For civilian aircraft, they generally do not need to fulfill separate flight plan notification obligations because they are under the air traffic control of the country managing the Flight Information Region (FIR) established by the International Civil Aviation Organization (ICAO). Therefore, even if an ADIZ is declared, freedom of navigation is not significantly restricted. However, foreign military aircraft not under air traffic control are, in principle, subject to notification requirements, which could be seen as an infringement on freedom of navigation. This issue is debatable, similar to the question of whether freedom of navigation is permitted for foreign warships in an EEZ.

An ADIZ can be viewed as analogous to the 'contiguous zone' under the United Nations Convention on the Law of the Sea (UNCLOS). It is a form of 'contiguous airspace.' The contiguous zone is a zone adjacent to the territorial sea, extending up to 24 nautical miles from the baseline of the territorial sea, where a state can exercise necessary control to prevent or punish violations of its customs, fiscal, immigration, or sanitary regulations. The contiguous zone, situated between the high seas and the territorial sea, serves to mitigate conflicts.

ADIZs are unilaterally established and declared by a country's air force based on the right to self-defense under international law for national security purposes. While the contiguous zone is established within a 24-nautical-mile limit in accordance with UNCLOS regulations, there are no clear international norms regarding the limits of ADIZs, making it common to declare broader areas. To date, there are no norms that can justify the establishment of ADIZs, nor norms that can prohibit them.

International Normative Evaluation of Related Countries' Actions

“It is difficult to consider China's recent actions as problematic from the perspective of international norms.”

“The issue of the ADIZ arose due to the perception gap, where China downplays the 'China threat theory' while the U.S. and Japan exaggerate it.”

The ADIZ was first introduced by the United States following Japan's attack on Pearl Harbor. South Korea's ADIZ (KADIZ) was also unilaterally declared under U.S. leadership during the Korean War to prevent Chinese military incursions into the West Sea and South Sea.

It is difficult to consider China's recent actions in declaring the China Air Defense Identification Zone (CADIZ) as problematic from the perspective of international norms. This is because, first, there are no clear international norms regarding the declaration of ADIZs outside of sovereign airspace. Second, the ADIZs of the United States and Japan were also declared unilaterally without coordination with China. Third, due to the nature of ADIZs, which inherently conflict with freedom of navigation in airspace outside of sovereign territory, there is no basis to conclude that CADIZ specifically restricts freedom of navigation more than others. The threat perceptions of the U.S. and Japan regarding CADIZ are exaggerated.

The current ADIZ controversy is closely related to maritime boundary issues. The CADIZ stems from considerations regarding Diaoyu Island (Senkaku Islands in Japanese), the First, Second, and Third Island Chains, and is ultimately an extension of China's strategy to protect its core maritime interests. In the past, due to limitations in its naval and air power, China adopted a defensive stance on maritime boundary issues such as territorial seas, contiguous zones, and EEZs in the region. However, since 2010, China has intensified its maritime power ambitions by pursuing offensive actions simultaneously in the South China Sea and East China Sea. The somewhat exaggerated concerns of the U.S. and Japan regarding CADIZ stem from China's recent assertive actions concerning maritime boundary issues.

China tends to downplay the 'China threat theory,' while the U.S. and Japan tend to exaggerate it, and the gap between them remains unbridged. China makes relatively little effort to alleviate neighboring countries' concerns about its military buildup, while neighboring countries tend to perceive China's actions as having overly aggressive intentions. The fact that the ADIZ has caused numerous problems in Northeast Asia can be attributed to this divergence in perceptions, with both sides moving on parallel tracks.

Prospects for Air Defense Identification Zone Issues in East Asia

“Although there is a theoretical possibility of armed conflict in areas where ADIZs overlap, it is unlikely to actually occur.”

“All three countries—China, Japan, and South Korea—adhere to the Flight Information Regions (FIRs) established by the International Civil Aviation Organization (ICAO), and there are no overlapping areas. Therefore, aligning ADIZs with FIRs in the future could be a solution to the problem.”

When ADIZ boundaries overlap with those of neighboring countries, the core issue becomes 'military aircraft.' If U.S. or Japanese military aircraft enter China's ADIZ (CADIZ) without prior consent, fighter jets from both countries may be scrambled for surveillance. In such a scenario, fighter jets from both nations would demand the other's withdrawal or warn of interception for national security reasons, creating a theoretical possibility of aerial combat. In practice, the U.S. has historically not recognized other countries' ADIZs when operating its military aircraft and continues to do so. China, Japan, and South Korea also conduct patrol flights with military aircraft in other countries' ADIZs without prior notification.

Realistically, the likelihood of actual armed conflict between relevant countries in overlapping ADIZ areas is not high. It is not a new phenomenon for Chinese fighter jets to scramble in response to U.S. reconnaissance aircraft flying near Chinese airspace. Even before China declared its ADIZ, Chinese fighter jets would be deployed when U.S. aircraft operated over China's EEZ. Despite this, there has never been an instance where aerial skirmishes escalated into actual aerial combat.

An example is the 2001 Sino-U.S. military aircraft collision incident. At that time, a U.S. Navy EP-3 reconnaissance aircraft was conducting reconnaissance flights over China's EEZ near Hainan Island, prompting China to scramble fighter jets. While Chinese fighter jets were flying in close proximity, issuing withdrawal orders and threatening to intercept the U.S. EP-3, one Chinese fighter jet was caught in the turbulence of the larger EP-3, resulting in the fighter jet's crash and the reconnaissance plane making an emergency landing on Hainan Island with partial damage. Relations between the U.S. and China were significantly strained in the early 2000s due to the U.S. bombing of the Chinese embassy in Yugoslavia in 1999, leading Chinese nationalists to demand severe retribution against the U.S. for the crash of the Chinese fighter jet. However, both U.S. and Chinese political elites handled the military aircraft crash incident with caution. Although it took considerable time to return the reconnaissance aircraft, the Chinese government quickly repatriated the U.S. reconnaissance crew. Thus, there have been numerous instances where U.S. and Chinese warships or military aircraft have been deployed simultaneously in border or airspace zones, monitoring each other, but these have never escalated into full-scale military confrontation. The 1996 Taiwan Strait crisis, which reached a near-war situation, should be considered an exceptional case stemming from the unique nature of the Taiwan issue.

The issue of overlapping ADIZs among China, Japan, and South Korea is unlikely to be resolved in the near future. Not only is there a lack of international law to mediate this, but even if there were norms to serve as principles, the issue of boundary demarcation in East Asia is currently difficult to resolve. For example, regarding the overlapping EEZ issue between China and Japan, despite the existence of the recognized international norm of UNCLOS, the coexistence of two principles acknowledged by this convention exacerbates the dispute. Japan advocates for the 'equidistance' principle, arguing that EEZs should be defined based on a median line in overlapping areas, while China insists on an 'equitable solution' based on the natural prolongation of the continental shelf, asserting that China should have a larger EEZ than Japan. Given that maritime boundary issues remain unresolved, it is difficult to expect aerial boundary issues to be settled. At present, the best course of action is likely mutual tacit acknowledgment of each other's ADIZs without raising further issues.

When seeking to establish norms for resolving future ADIZ issues, the Flight Information Regions (FIRs) established by the International Civil Aviation Organization (ICAO) can serve as a reference. FIRs are not only adhered to by China, Japan, and South Korea but also do not have overlapping areas. Therefore, establishing a principle of aligning each country's ADIZ with its FIR in the future could open a path toward resolving the issue.

South Korea's Response Strategy

“It was a very positive development to align the KADIZ and Incheon FIR, resolving the issue of jurisdiction over the airspace above Ieodo, using this incident as an opportunity.”

“By leveraging current diplomatic leverage, resolving the EEZ negotiations with China would present an opportunity for South Korea to turn a setback into a comeback.”

China's declaration of CADIZ has, in a way, provided South Korea with an opportunity to align the Incheon FIR and KADIZ, a move long delayed due to Japan's refusal to cooperate. Previously, the South Korean government attempted to negotiate with the Japanese government regarding the issue of the airspace above Ieodo being included in the Japan Air Defense Identification Zone (JADIZ). However, the Japanese government responded with non-decision-making or complicated the issue by threatening to include the airspace above Dokdo Island within JADIZ. With the recently announced CADIZ significantly overlapping with JADIZ in the disputed areas of the East China Sea, Japan, facing a potential confrontation with China, found it considerably burdensome to also create friction with South Korea over the relatively narrow issue of the airspace above Ieodo. Gaining Japan's support by expanding KADIZ to include the airspace above Ieodo is a highly positive achievement.

By effectively utilizing the diplomatic leverage gained from this incident to resolve the EEZ discussions with China, South Korea can seize an opportunity to turn a setback into a comeback. The waters around Ieodo have been a site of inherent diplomatic conflict due to overlapping boundaries between South Korea and China. The 2000 Korea-China Fisheries Agreement does not contain provisions regarding Ieodo. Consequently, both governments designate the waters around Ieodo as a 'joint fishing zone,' meaning 'a zone where the current fishing order is maintained in the absence of separate agreements between the two countries.' For a long time, the South Korean government has requested negotiations with the Chinese government to resolve the issue of overlapping EEZs, but has not received a positive response, leaving the EEZ boundary demarcation issue unresolved. By using the diplomatic advantage gained through China's CADIZ declaration to persuade and pressure China on the Korea-China EEZ issue, South Korea could establish a significant turning point for securing its national interests in the region in the long term.

Boundary demarcation is a fundamental system. Yet, even on this basic systemic issue, East Asian countries have failed to reach amicable compromises, which serves as the backdrop for numerous problems in the region. This is why discussions on regional cooperation in East Asia must begin with the issue of boundary demarcation. ■

The East Asia Institute (EAI) receives financial support for research on middle powers' diplomacy from The John D. and Catherine T. MacArthur Foundation. EAI conducts Smart Q&A interviews with domestic and international experts in video format, aiming to provide timely and in-depth analysis of current issues through question-and-answer sessions with experts in relevant fields. This manuscript was compiled by Kim Yang-gyu, a researcher at EAI's Center for Asian Security Studies, based on the interview content. The opinions expressed are those of the individual expert and do not necessarily reflect the views of the East Asia Institute. Please cite the source when quoting from Smart Q&A.