Japanese Strike Capabilities: Security Advantages for U.S. Alliance, Challenges to Overcome

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Japanese Strike Capabilities: Security Advantages for U.S. Alliance, Challenges to Overcome

August 16, 2021 29 min read Download Report
Bruce Klingner
Senior Research Fellow, Northeast Asia
Bruce Klingner specializes in Korean and Japanese affairs as the Senior Research Fellow for Northeast Asia.


It behooves Tokyo to develop the ability to reduce missile strikes against Japan and for Washington to develop more capable allies. However, constitutional, legal, budgetary, technical, and societal hurdles will need to be overcome. Japanese strike capabilities would be militarily beneficial but will be politically and diplomatically difficult. It will require a dedicated and powerful prime minister to convince the Japanese public to accept a dramatic expansion of Japan’s post-war security role.

Key Takeaways

Japan acquiring strike capabilities would augment the U.S. military in the Indo-Pacific and encourage other allies to increase their share of the security burden.

However, Japan and the U.S. will need to work together to overcome numerous constitutional legal, budgetary, technical, and bureaucratic obstacles.

Washington should urge Japan to develop long-range strike capabilities but incorporate them into the overall alliance structure with combined operational planning.

Responding to Asian security threats requires robust U.S. forces in the region and strong alliance partners. Japan’s unexpected cancellation of a strategic missile defense system in 2020 triggered a resurgence of debate about whether the country should augment its defenses by acquiring strike capabilities, i.e., the ability to conduct an attack against targets in an opponent’s country. Disagreements raged about whether developing such capabilities was a necessary response to escalating regional threats or whether it violated Japan’s pacifist constitution. There was little attention, however, to the modalities of strike systems, how they would be incorporated into Allied strategic plans, or the numerous challenges that will need to be overcome prior to deployment.

During the subsequent year, the issue faded from public discussion, due largely to the resignation last September of Japanese Prime Minister Shinzo Abe. During his lengthy tenure, Abe was a strong proponent of removing post–World War II restrictions imposed on Japan and regaining a “normal nation” status. Abe expanded Japan’s role on the world stage, loosened limitations on Tokyo’s exercise of collective self-defense, and oversaw a buildup of the country’s Self-Defense Forces (SDF).

Abe’s advocacy was less successful for Tokyo developing strike capabilities to target other nations that had contemplated or were contemplating attacks on Japan. Abe’s successor as prime minister, Yoshihide Suga, has not been a strong a proponent—instead devoting his attention toward domestic policy reforms and a myriad of challenges, including Japan’s response to COVID-19. Suga is less likely than Abe to spend his political capital and Japan’s limited defense budget on new capabilities that would face strong domestic and regional resistance.

While muted for now, however, the issue could quickly return to the forefront as a result either of North Korean provocations or increased United States pressure for Japan to assume a bigger regional security role.REF Given the relentlessly escalating regional security threats, Washington and Tokyo should be working closely to assess Japan’s need to develop strike capabilities. In so doing, however, they should be cognizant of the numerous constitutional, budgetary, technical, and bureaucratic obstacles.

Pursuing strike capabilities, or even the formal announcement to do so, would be extremely controversial with Japan’s populace and neighboring countries—and would require deft public diplomacy to overcome strong resistance to such a significant shift to Japan’s post–World War II security posture.

The Growing North Korean Missile Threat to Japan

Japan warned that its security environment is “changing at extremely high speeds [and] becoming more complex far more quickly than anticipated.”REF The Abe Administration assessed that “North Korea in recent years has launched ballistic missiles at unprecedented frequency, rapidly improving its operational capabilities such as simultaneous launch and surprise attack [which are] grave and imminent threats to Japan’s security and significantly undermine the peace and security of the region.”REF

Evolving Forces. North Korea’s evolving nuclear and missile forces provide the regime with the ability to conduct a surprise preemptive first strike, retaliatory second strike, and battlefield counter-force attacks. Pyongyang is producing a new generation of advanced mobile missiles that are more accurate and are mobile and solid-fueled, making them more difficult to locate and target. Some have maneuverable warheads, which provide a greater ability to evade allied missile defense systems.

During a crisis, Pyongyang could use threats of nuclear attacks to intimidate Tokyo to preclude the use of Japanese ports, airfields, and bases for U.S. and U.N. Command operations against North Korea. The regime practiced its war plan to strike U.S. bases in Japan by launching multiple missiles from numerous locations throughout the country under wartime conditions and simulating nuclear airburst attacks over South Korea and Japan.REF

Pyongyang also identified the cities of Kyoto, Nagoya, Osaka, Tokyo, and Yokohama as targetsREF and warned that “the Japanese archipelago should be sunken into the sea by our nuclear bomb. Japan is no longer needed to exist near us.”REF

Japan Responds with Missile Defenses

Spurred by the growing North Korean missile threat, Tokyo invested heavily in creating a two-layer ballistic missile defense. Japan has eight Aegis-equipped guided missile destroyers equipped with Standard Missile 3 (SM-3) interceptor missiles for exo-atmospheric interception of attacking missiles, enabling two to on-station for ballistic missile defense. Tokyo is enhancing the system by procuring SM-3 Block IB and IIA interceptor missiles, which have greater interception coverage than earlier models, simultaneous engagement capability, and enhanced ability against missiles equipped with decoys. The Patriot PAC-3 land-based system can engage short- and medium-range ballistic missiles in their terminal phase. Japan will upgrade the system to PAC-3 Missile Segment Enhancement to enable missile interception at a higher altitude and double the protected area coverage.REF

Cancelling Aegis Ashore. In December 2017, the Abe administration, citing growing missile threats to Japan, decided to augment missile defenses by building two Aegis Ashore missile defense sites to augment the two ballistic missile defense–capable Aegis-equipped destroyers. However, in June 2020, Japanese Defense Minister Taro Kono unexpectedly cancelled plans for the project due to the potential for the interceptor missile’s first-stage booster to fall onto populated areas. To prevent that danger, the missile would have required a 10-year, $1.8 billion refurbishment.REF

Other likely factors in the decision include the overall cost of the program, poor handling of the site-selection process, and government difficulty in overcoming Japan’s imminent domain laws that favor local landowners. The Aegis Ashore program was initially estimated to cost $2.15 billion to purchase, operate, and maintain over its 30-year operating period, but the total eventually increased to $4.1 billion.REF

After having warned of a deteriorating security environment, Tokyo abandoned a viable means of addressing a threat to the Japanese homeland and the U.S. forces stationed there. The Aegis Ashore units would have provided missile defense for the entire country, unaffected by weather or staffing shortages that have affected the Aegis ships. Moreover, the deployment of Aegis Ashore would have freed up Aegis ships for other missions, such as maritime security in the South China Sea or Indian Ocean.

Abe’s Advocacy for a Strike Option

After Kono’s decision, Abe’s ruling Liberal Democratic Party (LDP) created a policy committee, headed by former Minister of Defense Itsunori Onodera, to study alternative missile defense scenarios as well as to consider Japan developing strike capabilities against enemy missile targets. The committee recommended the following: “Our country needs to consider ways to strengthen deterrence, including having the capability to halt ballistic missile attacks within the territory of our adversaries.”REF The committee carefully avoided terms such as attack, strike, or offensive capability in their proposal.

After receiving the committee’s recommendations, Abe opined that missile defenses alone were insufficient for maintaining deterrence or protecting Japan. He called for Japan to pursue a new course in its national security policy that would allow for strike capability against enemy targets preparing for missile launches against Japan. Abe emphasized that this was compliant with international law, Japan’s constitution, the country’s defense-oriented security posture, and the terms of the U.S. alliance. Abe directed the government to create a new National Security Strategy, as well as formally make a decision on Japan acquiring strike capabilities by the end of 2020.REF

In December 2020, the Suga administration, which had assumed office after Abe resigned in September 2020, approved construction of two Aegis-equipped ships to replace the cancelled Aegis Ashore project. Internal Ministry of Defense documents indicate the ship-based alternative may cost twice the amount of the cancelled Aegis Ashore project.REF However, it postponed the decision on formally acquiring strike capabilities, instead relegating the issue to further study. Komeito, a Japanese political party and the LDP’s pacifist coalition partner, had opposed loosening restrictions on Japan’s ability to strike other nations—even when Japan faced imminent attack.

Debating Whether Strike Capabilities Are Constitutional

Japan’s intentions on acquiring strike capabilities are unclear due to differing views amongst policymakers, evolving viewpoints to growing missile threats to Japan, and the use of vague euphemisms to reduce potential opposition. Politicians have avoided terms such as “offensive missions” or “preemptive strike,” instead using less provocative nomenclature such as enemy base attack (or strike), proactive deterrence, proactive self-defense, self-defense counterattack, and stand-off defense.

Policymakers’ Views. The majority of Japanese policymakers who advocate for Tokyo to develop the ability to hit targets within an opponent’s territory emphasize that it would be exercised only after an initial attack on Japan. An enemy’s first salvo of missiles would be handled by Japan’s missile defenses, only after which Tokyo would initiate counter-attacks on their opponent’s missile launchers to prevent subsequent launches.

Some officials, however, have argued that the destructive capability of nuclear weapons requires the ability to preemptively strike an opponent even prior to an attack on Japan. Inherent in the debate is whether either option is compliant with Japan’s peace constitution.

Self-Defense. The dispute regarding whether Japan would be allowed to have such capability is not new and can be traced back to 1956 when then-Prime Minister Ichiro Hatoyama assessed that attacking enemy bases could be justified in terms of the right of self-defense. He stated, “If Japan were in imminent danger of an illegal invasion, and the method of invasion were a missile attack against Japan’s national territory, I simply cannot believe that the spirit of the Constitution requires that we merely sit and wait to die.”REF

However, Hatoyama stipulated that Japan would attack enemy missile bases only if there was an imminent and illegitimate act of aggression against Japan, that no other measures of self-defense were available, that the country would take the minimum measures necessary, and that Japan did so within the scope of self-defense.

It was argued that striking an enemy base when an attack is imminent was part of the nation’s right to self-defense under international law. The U.N. Charter, Article 51 stipulates, “Nothing in the present Charter shall impair the inherent right of individual or collective self-defense if an armed attack occurs against a Member of the United Nations.”REF

Preemptive Attack? Since that foundational statement, subsequent Japanese administrations consistently asserted that Japan had the authority to conduct attacks on enemy targets while concurrently delineating the differences that such attacks had with preemptive attack, which is not allowed by Japan’s constitution or international law.

In March 1999, Japanese Defense Agency Director General Hosei Norota stated that Japan’s constitution does not allow for a preemptive attack, which he defined as an attack “when it is inferred that there is a danger of an armed attack.”REF In 2003, Minister of Defense Shigeru Ishiba seemed to offer a different interpretation when he stated that Japan had the right to attack a target—such as a North Korean missile—if the opponent had only declared an intention to attack Japan and a missile had been raised to vertical in preparation for launch.

Under Ishiba’s interpretation, an actual attack on Japan was not necessary for Tokyo to initiate an attack on a missile in North Korea.REF However, subsequent statements over the years emphasized that Japanese counterattacks would only occur after Japan had been initially struck by missiles.

In 2013, Minister of Defense Itsunori Onodera declared, “When an intention to attack Japan is evident, the threat is imminent, and there are no other options, Japan is allowed under the law to carry out strikes against enemy targets.”REF Onodera emphasized, however, that such an option would be used only if Japan was attacked first, and therefore did not contradict the defensive nature of Japan’s Self-Defense Forces.REF Onodera’s comment was noteworthy since he was highlighting the deterrent value of having strike capabilities more than the security benefits gained from being able to attack opponent’s missiles.

U.S.–Japanese Security Consultative Meetings discussions at that time did not include mention of Japan acquiring strike capabilities in the joint statement or in the press briefing. However, concurrent reporting indicated that the U.S. Secretaries of State and Defense expressed opposition to the proposal.REF

In 2017, an LDP study group proposed that Tokyo develop a counterattack ability to conduct enemy base strikes, mentioning cruise missiles as a possible option.REF Like previous LDP studies, the recommendations for developing strike capabilities were not implemented.

In 2020, Defense Minister Kono argued that a preemptive first strike against an enemy missile launcher preparing to attack Japan would not violate the country’s constitution. Kono explained that such an attack would still be done out of self-defense, and he disagreed with a Diet member who asserted that enemy base strikes were allowable only after the enemy missile launch had occurred.REF Kono’s interpretation seems at odds with other officials’ depiction of what Japan was considering.

Changing Constitutional Interpretations

Japan’s legal interpretation of what is allowed under its peace constitution is not static. It has evolved in response to increasing regional threats, Japan’s improving military capabilities, and Tokyo’s perception of the strength of its alliance with Washington.

In essence, what the constitution allows has evolved very slowly toward a more active military posture. The creation of the Self-Defense Forces after World War II was determined to be unconstitutional…until it was not. Similarly, signing Japan’s defense treaty with the United States and allowing Japanese forces to participate in U.N. peacekeeping operations were both originally perceived as contrary to the constitution’s post-war restrictions but were eventually accepted. In subsequent years, Japan gradually adopted missions and deployed weapons that were originally deemed to be unconstitutional.

Japan’s adoption in 2015 of a less restrictive interpretation of its right to exercise collective self-defense is a case in point of something long assessed to be unconstitutional ultimately being implemented and accepted.REF The policy shift was the result of years of relentless advocacy by Abe to implement a change that was monumental in a Japanese context, but that was actually a quite minimalist and long-overdue response to rapidly growing regional threats. The passage of the legislation sparked large domestic protests, as well as handwringing by the country’s neighbors, who warned of a resurgence of Japanese militarism.

The Ministry of Defense’s 2020 White Paper commented that Japan’s defense capabilities are “subject to change according to the prevailing international situations, the level of military technologies, and various other factors.”REF Hinting at potential attacks on foreign nations, the policy document commented, “The use of the minimum necessary force to defend Japan under the right of self-defense in not necessarily confined to the geographic boundaries of Japanese territory, territorial waters, and airspace.”REF

Unaltered Shield-and-Sword Relationship

Tokyo developing stand-off or strike capabilities appears to alter the traditional “shield and spear” bilateral relationship with which Japan defends the country while the United States, acting on behalf of its ally, conducts any offensive attacks on foreign nations. While prime minister, Abe reportedly commented privately, “With the advent of new [North Korean] missiles, there’s a limit to what can be done with a shield. We have to have a halberd.”REF

However, Japanese officials have repeatedly affirmed there will be no change in the relationship, since any attack on foreign targets would be retaliatory rather than preemptive and undertaken to prevent additional attacks. In 2019, Prime Minister Abe emphasized during a Diet meeting that Japan has not changed its traditional defense policy and would concentrate on protecting itself in an emergency: “Under the division of roles between Tokyo and Washington, Japan depends on the attack capabilities of the United States for any strike against enemy bases.”REF

Also, in 2019, Defense Minister Takeshi Iwaya explained that Japan was not seeking to fundamentally change alliance roles, but that the planned air-launched stand-off missiles provide “the capability of striking enemies that are further away. Basically, they are for the defense of our remote islands. [But] we have to be able to respond to attacks that come from outside the zone as well…. We have a policy of being exclusively defensive, but we believe that the new equipment is in line with this policy.”REF

Benefits of Japanese Strike Capabilities

North Korea’s development of nuclear weapons escalated the risks of Tokyo relying solely on passive missile defense, which, if overwhelmed, would have catastrophic results. While effective, the cost of missile interceptors constrains Japan’s ability to match North Korea’s steadily expanding missile arsenal.

Increasing the Cost of an Enemy Attack. The most advantageous strategy would be to adopt a comprehensive strategy of robust missile defenses augmented with strike forces to suppress and attrite the number of attacking missiles to be defended against. Being able to hold enemy targets at risk increases the price of any attack on Japan, thereby enhancing deterrence and regional stability while degrading an opponent’s attempts at coercion.

Reducing Follow-On Attacks. A Japanese ability to “shoot the archer,” rather than intercepting all incoming arrows, would enhance allied capabilities to disrupt an opponent’s ability to conduct follow-on attacks and thereby reduce additional casualties and destruction. Conversely, a continued Japanese reliance on U.S.-only counterattacks could overtax America’s ability to respond to North Korea’s expanding and increasingly sophisticated missile force.

Augmenting Regional U.S. Capabilities. Japan acquiring strike capabilities would augment U.S. military capabilities in the Indo–Pacific region and exemplify U.S. requests for allies to do more to share the security burden by assuming greater responsibilities and roles. The U.S. National Defense Strategy declared, “[W]e expect allies and partners to contribute an equitable share to our mutually beneficial collective security, including effective investment in modernizing their defense capabilities.”REF

Looking beyond the North Korean threat, Japanese strike capabilities could be incorporated into new U.S. military strategies for the Indo–Pacific region. Admiral Phil Davidson, former head of U.S. Indo–Pacific Command, recommended a Pacific Deterrence Initiative, including plans for ground-based, long-range precision-strike fires in support of allied air and maritime operations targeting Chinese assets at considerable distance from the coast on the Chinese mainland.REF

Extended Deterrence Guarantee. Having indigenous strike capabilities, especially if integrated in an alliance structure, could ameliorate Japanese concerns about the continued viability of the U.S. extended deterrence guarantee. Prior to becoming Minister of Defense, Nobuo Kishi said, “The Japan–U.S. security alliance guarantees that the U.S. military is responsible for the role of ‘attack,’ but I do understand there is a concern that we shouldn’t rely solely on America to deal with a situation that could imperil our nation’s survival.”REF

In announcing the 2020 LDP committee recommendation for strike capabilities, former Minister of Defense Gen Nakatani commented, “[W]e cannot take for granted that the United States will retaliate if we are attacked. There is a need for us to enhance deterrence by developing our own retaliatory capability.”REF

Significant Hurdles to Implementation

While Japan acquiring strike capabilities would be militarily advantageous, there are numerous barriers to be overcome.

Defining Mission and Strategy. Having concluded that Japan is constitutionally allowed to have strike capabilities, Japan still needs to define the missions and parameters for such forces. Tokyo has yet to articulate a strike policy, targeting capability requirements, strategy, doctrine of employment, triggering events, procurement, deployment, or how offensive systems would train in Japan.

Currently, the only legal authority for Japan to use military force against another country would be under the “Development of Seamless Security Legislation to Ensure Japan’s Survival and Protect Its People” adopted in 2015.REF However, the political process for employing it is cumbersome and not conducive to responding quickly and efficiently to rapidly developing situations.REF Japan will need to incorporate strike options into enabling legislation, as well as develop effective crisis management and rapid decision-making procedures during a crisis—traits Tokyo has not previously demonstrated.

Japan should identify whether it is contemplating counterattacks only on North Korean missile launchers and units prior to a follow-on attack or a more extensive attack plan against a broader array of North Korean targets is envisioned. Mobile, solid-fueled missiles are extremely difficult to track and attack because they can be dispersed into the field, remain hidden until shortly before launch, and be quickly repositioned to follow-on launch sites. Japan does not currently have sufficient intelligence, surveillance, and reconnaissance capabilities to detect and monitor mobile missile targets nor the requisite systems to rapidly convert incoming intelligence data into targeting information for dynamic tasking by strike forces.

Tokyo will either need to purchase its own extensive systems for independent strike capabilities or rely on U.S. resources. It is a difficult choice. The former course would be extremely expensive, while the latter risks diverting or overwhelming American assets. It will also require Japanese missions to be part of a comprehensive allied attack plan with Japanese force integrated into an alliance command-and-control structure, which, to date, Japan has resisted, opting instead for parallel command structures.

The SDF services remain stove-piped with insufficient ability to communicate, plan, or operate across services. Japan’s inability to conduct joint operations across its own military services inhibits its capacity for combined operations with U.S. forces. This is unlike, for instance, the U.S. security relationship with South Korea, where there is an integrated security structure.

Identifying Strike Systems

Japan previously announced plans to procure several medium-range cruise missiles to be mounted on F-15 and F-35 aircraft and Aegis-equipped ships for attacking enemy ground and ship targets. Tokyo will purchase the 500-km-range Joint Strike Missile, the 900-km-range AGM-158B Joint Air to Surface Standoff Missile Extended-Range, and the 900-km-range AGM-158C Long-Range Anti-Ship Missiles. Japan is also developing 1000-km-range hypersonic guided missiles that can fly at five times the speed of sound.

Long-Range Missiles? However, Defense Minister Itsunori Onodera emphasized that these “stand-off missiles will be introduced exclusively for the purpose of defending Japan, [sic] they are not intended for the so-called enemy base attack.”REF Chief Cabinet Secretary Katsunobu Kato insisted the planned long-range missiles were intended to strengthen Japan’s stand-off defense capabilities by allowing Japanese forces to respond defensively to threats from a safe distance.REF

While some LDP legislators have proposed that Japan purchase 1300-km-range Tomahawk cruise missiles,REF Tokyo has yet to identify what strike system or systems it seeks for long-range strike missions. One possibility, announced by the Suga administration in December 2020, is to develop long-range missiles with sufficient range to attack North Korea.

The new missiles are to be an upgraded, extended-range version of the Type 12 surface-to-ship missile. The original truck-mounted Type 12 had a range of 200 km, which had been increased to 400 km in the ship-mounted Type 17 modification. The new missile’s range would be augmented to 900 km with a possible eventual goal of 1,500 km. The missile would be able to target an opponent’s ground targets, as well as ships, and to be launched from Japanese ground-based launchers, ships, and potentially F-15J fighters.REF

Cruise vs. Ballistic Missiles. For long-range attack, cruise missiles such as Tomahawks are highly accurate, could be acquired and deployed relatively quickly, and are less costly than some alternatives. A Tomahawk is considerably cheaper than a SM-3 Block IIA ballistic missile defense interceptor—$1.8 million for the former versus $18.4 million for the latter.REF

On the other hand, cruise missiles are relatively slow and inflict less damage than ballistic missiles. Cruise missiles may be too slow to be used against time-sensitive mobile missile targets since it would take one hour to reach a target 800 kilometers away. Cruise missiles would also be more likely to be intercepted by advanced air defense systems than ballistic missiles.REF Ballistic missiles could attack enemy targets at long-range, very quickly, with great lethality, and with impunity from air defenses. However, ballistic missiles are more costly and would take longer to convert existing systems or develop new systems.

Japan could seek to develop a mixture of cruise and ballistic missiles or rely solely on cruise missiles against North Korean fixed targets while the United States maintains the mission of attacking North Korean mobile missiles.

How to Pay for New Military Capabilities

Developing, deploying, and maintaining new military capabilities is costly in both monetary terms and lost opportunities. As with any budget, new requirements either must be accomplished through additional overall funding or through decreased emphasis on existing missions, including stretching out development timelines. In its most recent security documents, Japan articulated ambitious weapons acquisition plans and extensive security initiatives, and pledged to develop new capabilities in cyber, space, and electromagnetic domains.

During his time in office, Prime Minister Abe was rightly praised for reversing Japan’s steadily declining defense budget and implementing record high spending on the SDF. However, Japan’s defense budget increases rose only slightly in real terms, and overall spending remained capped at 1 percent of Japan’s gross domestic product (GDP)—despite escalating security threats. According to the CIA World Factbook, Japan’s per capita spending on defense is 125th in the world.REF Tokyo’s constrained defense expenditures hinder the country’s ability to fulfill its ambitious security plans, let alone a major new mission.

In order to develop strike capabilities, Japan will have to significantly augment defense spending and break the arbitrary, politically self-imposed 1 percent of GDP cap. Otherwise, the initiative will come at the expense of other critical defense missions.

Putting In the Effort

Prime Minister Hatoyama’s 1956 statement provided the foundation for allowing Japanese strike capabilities, but nearly 70 years later, Japan continues to debate doing so. Progress in altering Japan’s security posture has always lagged behind faster-moving regional threats. Any change in Japan’s security posture requires a great amount of time, effort, and outside pressure to overcome political and public resistance.

For Japan to adopt a base strike policy would require a similar concerted effort by strike advocates to overcome monumental domestic and regional resistance. Abe’s 2015 collective self-defense legislation led to large protests in Japan. Similarly, Tokyo’s decision to cancel the defensive Aegis Ashore project due to local resistance does not bode well for gaining approval for deploying offensive systems to enable strike capabilities.

Then there is the matter of leadership. Prime Minister Suga or a successor must demonstrate Abe’s drive to spend the effort, political capital, and funding to bring such a major shift to Japan’s security posture to fruition.

Without concerted focus, given Japan’s propensity for deferring controversial issues and slow decision-making processes, even a formal decision on adopting the option could be years away.

Overcoming Resistance

The Japanese populace remains deeply suspicious of the use of the military as a policy instrument—and fearful that any easing of constraints will lead Japan into military conflict. Komeito, the LDP’s coalition partner, has indicated it does not support developing long-range strike capabilities. Japan’s neighbors, all of which have long-range strike capabilities, would seek to deny Tokyo the same capability by warning that any enhancement in the country’s military capabilities risks a resurgence of imperialistic militarism.

If the United States is perceived as encouraging or “allowing” Japan to gain strike capabilities, South Korea could react negatively to Washington, as well as to Tokyo. Japan augmenting its ability to defend itself against North Korean attack could exacerbate tensions amongst U.S. allies and undermine trilateral defense cooperation.

Public Diplomacy. Tokyo will need to engage in a lengthy, determined public diplomacy effort to articulate the strategic necessity of developing strike capabilities and the circumstances under which they would be used. The failure to overcome local resistance to the defensive Aegis Ashore system illustrates the difficulties in deploying an offensive system. Strike units would also need to engage in local training to maintain proficiency.

Washington should affirm that the integration of Japanese strike capabilities into an alliance framework would preclude Tokyo being able to conduct strikes unilaterally. South Korean warnings of a return to militarism ignore Japan’s constitutional and legislative constraints; military strategic guidance documents; democratic system including opposition parties, public opinion, and media; a limited defense budget; and 70 years of non-belligerent security policy.

What Should Be Done

Japan should work toward developing long-range strike capabilities to better protect its territory and people, augment alliance deterrence and defense capabilities, and assume a larger security role in the Indo–Pacific region.

Washington should urge Tokyo to:

  • Augment its missile defenses. Canceling Aegis Ashore in favor of two additional Aegis-equipped ships does not provide a comparable level of missile defense. The land-based version would have protected the entire country, been unaffected by weather or staffing shortages of Aegis ships, and freed U.S. and Japanese ships for other missions. Strike capabilities would not be a substitute for missile defenses. Tokyo should review its missile defense plans to ensure it possesses robust defenses against North Korea’s increasingly sophisticated missiles.
  • Assess necessary parameters of strike forces. While implementing yet another policy committee seems designed to delay implementation, it is necessary to ensure the right option is chosen and then be able to be justified to the public. Rather than again debating whether Japan is allowed to pursue strike capabilities, this time the focus should be on how to implement a deterrence through strike option. There should be a thorough assessment of strike policy, strategy, means of employment, necessary systems, and methods of deployment and training as well as the benefits, costs, and risks of pursuing a strike option.
  • Integrate Japanese strike capabilities into an alliance framework. Since the Self-Defense Forces lack requisite intelligence, surveillance, and other capabilities necessary for dynamic real-time targeting, Japan should incorporate any strike missions into the overall alliance structure. This would likely include all Japanese sensors and platforms associated with the strike mission. Combined operational planning and command-and-control would augment alliance capabilities, reduce redundancy, and enable more effective implementation. The allies should assess any necessary changes to existing roles, missions, and capabilities.
  • Improve alliance military coordination. The lack of a unified U.S.–Japan command inhibits combined operations. A U.S.–Japan Combined Forces Command, like that of the United States and South Korea, would be difficult to implement. But Washington and Tokyo should seek means to enhance the ability to conduct joint and combined operations.
  • Increase the defense budget. Prime Minister Suga should convince the Japanese legislature and public that steadily rising threats require more than incremental adjustments to the defense budget. Even prior to raising the potential for strike missions, Tokyo announced comprehensive new strategies, missions, and ambitious procurement plans—but did not couple them with the resources needed to implement them. Japan must move above its self-imposed limit of spending only 1 percent of its GDP on defense. Japan should move to a higher level, perhaps the same 2 percent level to which NATO has committed.
  • Create a trilateral security initiative. Such a 2+2+2 meeting of the U.S., South Korean, and Japanese foreign and defense ministers should develop joint strategies for addressing common threats and objectives. The allies should develop comprehensive trilateral plans for responding to North Korean provocations and crisis management. Early initiatives could include standardizing logistic cross-servicing, information-sharing protocols, and overseas deployments.
  • Enhance public diplomacy efforts to articulate that the North Korean and Chinese threats necessitate Tokyo augmenting its defense capabilities, including exploring strike options. Taking steps to respond to other nations’ long-range attack capabilities does not threaten regional stability. Washington and Tokyo should discuss whether it is more advantageous to announce that Japanese strike missions would be initiated only after an initial enemy attack and in consultation with the United States to mitigate some South Korean concerns of Japanese attack options or to adopt a more ambiguous policy to enhance deterrence.


For both Japan and the United States, balancing the benefits and risks of Tokyo developing strike capabilities will be difficult. It behooves Tokyo to develop the ability to reduce missile strikes against Japan and for Washington to have more capable allies. To get there, constitutional, legal, budgetary, technical, and societal hurdles will need to be overcome. It will require a dedicated and powerful prime minister to convince the Japanese public to accept a dramatic expansion of Japan’s post-war security role.

Bruce Klinger is Senior Research Fellow for Northeast Asia in the Asian Studies Center, of the Kathryn and Shelby Cullom Davis Institute for National Security and Foreign Policy, at The Heritage Foundation.


Bruce Klingner
Bruce Klingner

Senior Research Fellow, Northeast Asia