The introduction of long-range cruise missiles that the Defense Ministry is seeking in its fiscal 2018 budget runs the risk of being taken as an indication that Japan is looking to acquire a capability to strike enemy bases in the face of the growing threat posed by North Korea’s nuclear weapons and ballistic missiles. The government says the cruise missiles are meant for protection of Aegis vessels of the Maritime Self-Defense Force on missile defense missions and for defending Japan’s remote islands against enemy invasion, and denies that their introduction reflects any change to the nation’s exclusively defense-oriented defense policy. But adding the cruise missiles to the SDF’ arsenal should be considered from a more comprehensive viewpoint, including how the move would be perceived by other countries in the region and how that could affect the security situation surrounding Japan.
The Defense Ministry has sought an additional ¥2.2 billion in its budget request for acquiring the JSM missile by Norway’s Kongsberg Defense & Aerospace and for research on Lockheed Martin Corp.’s JASSM-ER and LRASM missiles. The JSM, with a range of about 500 km, will be mounted on the Air Self-Defense Force’s F-35 stealth fighter and is planned for deployment in fiscal 2021, and the U.S.-built JASSM-ER and LRASM missiles, each with a range of roughly 900 km, will be considered for possible mounting on F-15 fighters.
A cruise missile with a range of 900 km could technically enable Japan to hit North Korea’s ballistic missile launch facilities without approaching the Korean Peninsula. Based on a 1956 statement by then Prime Minister Ichiro Hatoyama, the government maintains that when there is a pressing danger of a missile attack on Japan — and when there are no other means to defend the nation against such an attack — a minimum necessary strike on the enemy base to forestall the missile attack will be legally within the range of self defense. Still, the government has so far not obtained the capability for such an attack.
The government, however, denies that introduction of the cruise missiles are meant for the purpose of striking enemy bases. While noting that the decision for their introduction was made in view of the changing security circumstances surrounding Japan, Chief Cabinet Secretary Yoshihide Suga says Japan continues to rely on its security ally, the United States, for the capability to attack enemy bases and the government has no plans to review that division of roles. Defense Minister Itsunori Onodera also says acquiring the cruise missiles are not inconsistent with the government’s defense-only defense policy under the war-renouncing Constitution.
But Onodera, before being tapped for a second time as defense chief in the Cabinet of Prime Minister Shinzo Abe in August, headed the ruling Liberal Democratic Party’s research commission on national security when the panel in March proposed to the government that it promptly study acquiring the capability to strike enemy bases with cruise missiles with a view toward neutralizing North Korea’s ballistic missile launch facilities. Abe himself told the Diet in November that his administration is not currently looking into obtaining enemy base-strike capabilities but added that the government has a duty to consider various options in view of the reality in the nation’s increasingly severe security environment.
North Korea’s nuclear weapons and ballistic missile development pose a growing security menace to Japan. Pyongyang fired two ballistic missiles that flew over Japan this summer, and is believed to have developed an intercontinental ballistic missile capable of hitting the U.S. mainland. Japan needs to beef up its missile defense capabilities. But whether it should acquire the capability to strike North Korea’s missile launch facilities — which if carried out would likely be a pre-emptive strike since it would need to be done before an imminent missile launch takes place — is a different issue. Acquiring cruise missiles alone will not give Japan such a capability. The nation will have to develop an intelligence system to gather target-acquisition information and the capability to penetrate the enemy’s air defense system.
In terms of deterrence against North Korea, it should be considered whether Japan should acquire the capability to attack overseas bases when, as the government emphasizes, the U.S. already has it. What should also be considered is the international repercussions of such a decision, including the risk of sending the wrong signal about Tokyo’s intentions. The introduction of cruise missiles to the SDF’s arsenal, which would rouse such questions, should be carefully discussed in the Diet.