Japan fast-tracks US Tomahawk missiles purchase

Japan’s accelerated purchase of US-made Tomahawk missiles marks a significant shift in its defense strategy. Given threats from North Korea and China, a closer look at the factors driving this decision is called for.

This month, multiple media sources reported that Japan – following a Pentagon meeting between Japanese Defense Minister Minoru Kihara and US Defense Secretary Lloyd Austin – would speed up its planned acquisition of US-made Tomahawk cruise missiles by a year.

Japan had planned to purchase 400 Tomahawk Block V missiles over fiscal years 2026 and 2027 at the rate of 200 missiles per fiscal year. However, due to increasing missile threats from China and North Korea, some of Japan’s missile purchases are to be substituted with the older Tomahawk Block IV, which will be acquired in fiscal years 2025 to 2026. Japan has plans to arm all eight of its Aegis destroyers with Tomahawks by 2027.

The Tomahawk Block IV is the current version of the long-serving cruise missile, which entered service in 1983. It has a range of 1,600 kilometers, can be fired from ships and submarines, can loiter for hours, and has a datalink that allows it to change course on command.

In contrast, the Tomahawk Block V has upgraded navigation and communication systems, can strike moving targets at sea, and has a joint multi-effects warhead to hit more diverse land targets.

While Kihara stated that the US has indicated its support for the expedited acquisition, congressional approval is still pending.

Japan’s acquisition of Tomahawk missiles aims to enhance its defense capabilities by adding counterstrike capabilities.

This move comes after a detailed analysis of the country’s security environment, as outlined in Japan’s 2023 defense white paper. The paper notes various challenges, from China’s drone activities to North Korea’s missile launches.

The new policy was endorsed by US President Joe Biden during a meeting with Japanese Prime Minister Fumio Kishida, signaling a foundational reinforcement of Japan’s defense capabilities in a rapidly degenerating security landscape.

The decision to expedite missile acquisition has also prompted calls from security experts for the Japanese Ministry of Defense to provide a comprehensive public explanation. Given the geopolitical complexity and rapidly changing defense needs, such a step could elucidate the strategic rationale behind Japan’s shifting defense priorities.

China and North Korea’s missile capabilities and growing strategic ties have influenced Japan’s decision to accelerate its Tomahawk missile procurement for counterstrike capabilities.

In a November 2022 Heritage Foundation report, Bruce Klinger points out that North Korea is conducting many missile tests with the ultimate goal of gaining tacit approval of its breach of United Nations resolutions. Klinger says the country’s missile launches have become routine, and it relies on obstructionism from China and Russia at the UN Security Council to achieve this.

Depicting its military provocations as justified responses to resumed US-South Korean military drills, Pyongyang aims to coerce the allies into reducing future exercises, as highlighted by Klinger.

Concerning nuclear weapons, Klinger says that North Korea was estimated to have manufactured approximately 30 to 60 nuclear warheads or enough fissile material for such weapons by the year 2017. Furthermore, he says North Korea can produce seven to twelve more warheads annually.

He states that by 2027, North Korea could have 200 nuclear weapons. The regime has conducted six nuclear tests. Washington and Seoul have declared that Pyongyang has completed preparations for a seventh nuclear test.

Klinger mentions that North Korea can deliver nuclear weapons against targets in South Korea, Japan, Guam, Hawaii and the continental US. He says it is now producing a new generation of advanced mobile missiles that are more accurate, mobile and difficult to detect and target.

Further, Victor Cha and Katrin Fraser Katz mention in an April 2022 report for the Center for Strategic and International Studies (CSIS) that North Korea is increasingly willing to accept risks in missile testing to strengthen its missile program, as it has a favorable environment for missile tests while the US is distracted by the war in Ukraine. They add that China and Russia are deepening their strategic partnership.

North Korea’s desire to display military progress and maintain loyalty within the regime, coupled with its internal situation and economic conditions, serve as motivations for conducting tests, according to Cha and Katz.

They also note North Korea no longer needs much outside help for its nuclear program, as it can obtain necessary components and materials from the global market. Also, they say North Korea has an advantage in attaining an offensive win because the required capabilities are less expensive than those needed for the US to defend itself.

China’s missile threat to Japan was underscored during its August 2022 military drills around Taiwan, where five missiles landed in Japan’s exclusive economic zone.

In a June 2020 article in the peer-reviewed Asian Security journal, Jaganath Sankaran mentions that China’s missile capabilities are intended to diminish the projection of US and allied military power, focusing heavily on vital air and naval bases.

Sankaran notes that Japan’s Kadena and Futenma air bases are the only two bases within US fighters’ unrefueled combat radius of the Taiwan Strait. He says these bases are uniquely suited for operating larger aircraft and for takeoffs but suffer from a lack of substantial defensive air shelters, a lapse that could dilute US air power projection.

Sankaaran also mentions that in the event of a Taiwan conflict, aside from Kadena and Futenma, other US bases such as Misawa, Iwakuni and Yokota, could be targeted by Chinese missile strikes.

China and North Korea may also work together to fracture US alliances in Northeast Asia. In a February 2022 article for the Freeman Spogli Institute for International Studies (FSI), Oriana Skylar Mastro and Sungmin Cho highlight the potential danger posed by North Korea’s missile capabilities as a significant factor driving Japan and South Korea’s diplomatic approach towards China.

Mastro and Cho say that the heightened threat of North Korean missile attacks incentivizes Japan and South Korea to avoid alienating China, which they hope will help keep Pyongyang in check. They say that Japan and South Korea, being threatened by the increased risk of missile attacks from North Korea, are motivated to maintain positive relationships with China to keep Pyongyang in line, thereby weakening the alliances between the US and its partners in Tokyo and Seoul, as both nations seek to avoid antagonizing China.

Mastro and Cho mention that North Korea’s missile capabilities are helping accomplish this task by more effectively threatening Japan and South Korea and increasing their citizens’ doubts about the efficacy of US extended deterrence and missile defense.

Although it is unclear how Japan will employ its counterstrike capabilities, it has made substantial efforts to delineate critical operational concepts.

In an article for the Carnegie Endowment for Regional Peace, James Schoff and other writers note that Japanese leaders have differentiated between enemy base strike capability, missile prevention/interdiction capability,  standoff missile defense capability, counterattack, pre-emptive strike, missile defense, and comprehensive air and missile defense.

Schoff and others note these operational concepts were framed with specific limits in mind – that Japan can take only the “minimum measures unavoidably necessary” when “no other measures” of self-defense are available in the face of an “imminent illegal invasion.”

Further, the US and Japan may have their work cut out for them to strengthen their longstanding alliance. In a July 2023 article for CSIS, Yohsuke Aoki notes that while the acquisition of counterstrike capabilities will positively impact the US-Japan alliance as joint operations will improve and enhance deterrence, the US and Japan have not integrated the Joint Operation Command (OPCON) under their alliance for various reasons.

Aoki notes that Article 9 of Japan’s constitution and strategic goals that differ from those of the US make it difficult to integrate OPCON. Nevertheless, he says establishing a joint operation coordination center could improve the two countries’ command and control (C2) relationship.

Aside from that, he recommends that Japan should establish a permanent joint headquarters for its Self-Defense Forces (SDF); that the US should consider rearranging the geographical allocation of warfighting commands in the Indo-Pacific; and that bilateral dialogue be undertaken to objectively analyze the advantages and disadvantages of a parallel C2 structure.