Aegis Destroyers and Ballistic Missile Defense in Japan and South Korea

The Aegis combat system is quickly becoming the hallmark of sophisticated navies. Specifically, it is an advanced command and control, and an integrated weapons system, which features anti-submarine warfare systems, anti-aircraft warfare systems, the Phalanx CIWS to defend against anti-ship missiles, and Mark 41 Vertical Launch system. Simply put, Aegis uses high-powered computers and radar to track and guide weapons to enemy targets. It was developed by RCA, which was sold to various other American electronics corporations before being absorbed by Lockheed Martin which currently produces the systems. The US Navy has employed the Aegis system on its ships since the 1980s; it is also deployed by the navies of Spain, Norway, Japan, and South Korea. Australia and NATO forces intend to employ the system in the next few years to bolster their missile defense capabilities.

South Korea

ROK bought Standard Missile (SM)-2s in 2009 which would ultimately be used on Aegis destroyers. Aegis ships also have SPY-1D radar designed for early warning. In 2012 ROK also purchased Green Pine  land-based radar from Israel. South Korea’s Aegis ship is the Sejong Daewang (“Sejong The Great”) Class destroyer, aka KDX-III (Korean Destroyer III): a guided missile destroyer, jointly produced by Lockheed Martin and Hyundai Heavy Industries. The KDX-III is nearly identical to the American Arleigh Burke Class destroyer, except for its longer hull which makes it the largest surface ship in the world to carry the Aegis system. Though the ROK’s destroyers carry the Aegis radar tracking software they do not currently have interceptors. The ROK announced this past summer that it would upgrade from SM-2s to SM-6s by 2016, and a budget proposal accepted by the Joint Chiefs of Staff shows plans to procure three additional Aegis destroyers by 2020.

Japan

Japan’s BMD is comprised of six SM-3 missiles on their four Aegis destroyers, and the PAC-3 Patriot system. Tokyo is increasing the number of SM-3s from six to eight over the next ten years.

Last year PAC-3 was deployed in Okinawa and Tokyo’s Ministry of Defense HQ in a symbolic demonstration of capability, obviously not practical as using the missiles would, for instance, shatter every window in Shinjuku. Similar demonstrations of defense capability were made in 2009 and 2012 during North Korean missile threats.

Such demonstrations are more show than substance. Japan has other concerns aside from North Korean aggression: stagnant economy, territorial disputes with China, the Fukishima fallout, and the abduction of Japanese citizens by North Korea which is seen as far more pressing than the DPRK nuclear/missile threat, and the assurance of US alliance makes BMD even less of a priority—yet, the Japanese have still chosen to keep those four very expensive Aegis-equipped boats.

Regional dynamics

Japan has a high level of cooperation with the US, not least of which involved the US-Japan Defense Pact and the high assurance value of American military exercises in the region. This starkly contrasts to the minimal cooperation in missile defense between South Korea and Japan, and between South Korea and the US. While the Japanese are content with relying on the Americans for missile defense, South Korea is moving toward an increasingly independent missile defense system.

North-East Asian ADIZs

South Korea declared yesterday that it is expanding its Air Defense Identification Zone to include the submerged Ieodo rock, overlapping China’s ADIZ, to take effect on 2013-12-15. The South Korean announcement comes as a reaction and condemnation of China’s ADIZ, announced last month. Beijing has expressed regret.

The Chinese ADIZ is remarkable not because there is no precedent for zones of this nature, but because it effectively claims the need to be informed of any aircraft flying within the zone, which includes international airspace (as do other ADIZs) and, more controversially, it overlaps neighboring ADIZs. The entire purpose of an ADIZ is to eliminate confusion about nearby aircraft and to intercept enemy aircraft before it gets too close to sovereign airspace; but because China’s and South Korea’s ADIZs overlap with each other (and Japan’s), they are likely to cause rather than reduce confusion. Aircraft flying near Ieodo or the disputed island territories may face conflicting communications orders from multiple states, and potentially multiple attempts at interception. ADIZs are not explicitly included in international law and states are not obligated to abide by them, though they generally do in the spirit of collective security and in the interest of avoiding accidents.

Needless to say, Japan, South Korea and the US are not on board with China’s ADIZ declaration, rightly worrying that it lends to instability in the region.

In defiance of China’s announcement, South Korea conducted an air and sea exercises near South Korea’s Ieodo rock, which sits squarely within China’s ADIZ. The exercise included 2 P-3C patrol boats and 1 of South Korea’s 3 Aegis destroyers.

Japan also demonstrated noncompliance, scrambling 2 fighter jets against Chinese reconnaissance aircraft on the day of the announcement. South Korean and Japanese ADIZs immediately border each other but do not overlap.

Last week 2 American B-52 bombers entered China’s recently announced Air Defense Identification Zone (ADIZ) without notifying Beijing beforehand. The mission, an allegedly routine exercise called “Coral Lightning”, flew over the Senkaku/Diaoyu Islands on 2013-11-25. Secretary Hagel called China’s ADIZ “destabilizing”, further noting that “This announcement by the People’s Republic of China will not in any way change how the United States conducts military operations in the region.” The Chinese Defense Ministry claimed, “China’s armed forces will adopt defensive emergency measures to respond to aircraft that do not cooperate in the identification or refuse to follow the instructions,” yet the Pentagon said the exercise occurred “without incident“.

Military confrontation appears unlikely. Beijing is facing embarrassment, but beyond that consequences will be benign. It is probably too much to hope for a cooperative international effort to regulate ADIZs so as to avoid similar political disputes in the future.