By the CSIS Asia Team: Michael Green, Nicholas Szechenyi, Victor Cha, Bonnie Glaser & Christopher Johnson

U.S. B-52’s operating from Guam have flown through China’s recently announced air defense identification zone. Japanese and ROK military aircraft have followed suit. Source: Mateus_27:24&25’s flickr photostream, U.S. Government Work.

The People’s Republic of China (PRC) Ministry of National Defense (MND) announced the creation of the East China Sea Air Defense Identification Zone (ADIZ) on Saturday, November 23. The MND also announced Aircraft Identification Rules for the ADIZ, which include a warning that “defensive emergency measures” would be adopted to respond to aircraft that refuse to follow the instructions. The zone overlaps the existing ADIZ of Japan, South Korea, and Taiwan. China’s ADIZ covers the disputed Senkaku/Diaoyu Islets claimed by China, Japan, and Taiwan. One day following the announcement, China conducted two aerial patrols over the area involving Tu-154 and Y-8 aircraft, prompting the Japan Air Self-Defense Force to send two F-15 fighter jets to intercept them. The announcement elicited immediate responses from Japan, the United States, the Republic of Korea (ROK), Australia, and Taiwan.

How did the United States and regional allies respond?

Secretary of State John Kerry and Secretary of Defense Chuck Hagel issued separate statements expressing U.S. concerns. Kerry called China’s move “an attempt to change the status quo in the East China Sea” and warned that its “escalatory action will only increase tensions in the region and create risks of an incident.” Hagel noted that the move “increases the risk of misunderstanding and miscalculations.” He reaffirmed U.S. policy that Article V of the U.S.-Japan Mutual Defense Treaty applies to the disputed islands and that the Chinese announcement would have no bearing on U.S. operations. On November 26, a pair of U.S. B-52s from Guam flew through the contested area to assert U.S. prerogatives.

Prime Minister Shinzo Abe of Japan denounced China’s declaration as a dangerous attempt to change the status quo in the East China Sea through coercion, vowed to protect Japan’s air and sea space, and demanded that Beijing “revoke any measures that could infringe upon the freedom of flight in international airspace.” Foreign Minister Fumio Kishida stated that Japan would coordinate closely with the United States, the ROK, and others on demanding a revocation of the ADIZ measures. Vice Foreign Minister Akitaka Saiki summoned China’s ambassador to Japan, Cheng Yonghua, to the Foreign Ministry and lodged a formal protest against the ADIZ announcement, repeating the prime minister’s demand that China revoke the measures and dismissing their validity given Japan’s position that the Senkaku Islands are an inherent part of the territory of Japan. Defense Minister Itsunori Onodera stated that Japan’s Self-Defense Forces would work with the U.S. military to coordinate monitoring activities.

The ROK Foreign Ministry summoned Minister Counselor Chen Hai of China on Monday, November 25, to express its reservations over China’s unilateral drawing of the ADIZ, as did the ROK Ministry of National Defense via the Chinese embassy’s defense attaché. Deputy Defense Minister for Policy Yoo Jeh-seung of the ROK also noted that Seoul cannot recognize the ADIZ and stated that the ROK would maintain its jurisdictional right to waters around the disputed Ieodo/Suyan Rock.

Australia summoned China’s ambassador to voice its concerns, and Foreign Minister Julie Bishop issued a statement. So far, no Southeast Asian governments have followed suit. Regional airlines such as Singapore Airlines, Qantas, and two Japanese airlines initially said they will give China advance notice of flight plans through the zone.

Why has China’s ADIZ prompted such negative responses?

Beijing’s action further increases tension in the territorial dispute between China and Japan at a time when that bilateral relationship is already severely strained and heightens the risk of an accident. There is a very large overlap between China’s ADIZ and Japan’s ADIZ. When aircraft from either country fly in this overlapping area, the other side is likely to scramble fighters and intercept the intruder. If intercepts are not conducted safely and in accordance with international norms, a collision is possible. Recall that in 2001 a Chinese fighter jet that was conducting aggressive intercepts collided with a U.S. surveillance plane, which resulted in the Chinese pilot’s death, the forced landing of the U.S. EP-3 on Hainan Island where its 24-member crew was held for 11 days, and a crisis in U.S.-China relations.

Moreover, China’s Aircraft Identification Rules make no distinction between aircraft flying parallel with China’s coastline through the ADIZ and those flying toward China’s territorial airspace. Secretary of State Kerry highlighted this issue in his statement, saying that the United States “does not apply its ADIZ procedures to foreign aircraft not intending to enter U.S. national airspace,” implying that the United States would not recognize China’s claimed right to take action against aircraft that are not intending to enter its national airspace. Secretary Hagel stated that the United States would not change the way it conducts military operations in the region. Some Chinese may believe that a kinetic action against a Japanese aircraft in disputed air space near the Senkakus would not provoke a U.S. response because Washington is neutral on the issue of sovereignty over the islands. Secretary Hagel’s reiteration of U.S. commitments to Japan under the U.S.-Japan Security Treaty is important in this regard and should help to prevent Chinese miscalculation.

The problem for the ROK is that China’s ADIZ overlaps with Korea’s ADIZ off the southern island of Jeju, airspace already patrolled by the ROK Air Force. Included within the Chinese zone is a ROK-controlled submerged rock known as Ieodo in Korean, ownership of which has historically been disputed between the ROK and China. The ROK built the Ieodo Ocean Research Center, an unmanned scientific station, on the rock in 2003, despite great objections from the Chinese. The ROK Navy includes Ieodo within its area of operations, increasing the potential for maritime conflict between the ROK and China.

Dr. Michael J. Green is Senior Vice President and holds the Japan Chair at CSIS. Mr. Christopher K. Johnson is a Senior Adviser and holds the Freeman Chair in China Studies at CSIS. Dr. Victor Cha is a Senior Adviser and holds the Korea Chair at CSIS. Ms. Bonnie S. Glaser is a Senior Adviser for Asia with the Freeman Chair in China Studies at CSIS. Mr. Nicholas Szechenyi is a Senior Fellow and Deputy Director of the Japan Chair at CSIS.