This article first appeared on Pacific Forum and is republished with permission. Read the original here.
KDDI’s cable-laying and repair capacity, Japan’s intervention in the Makino Milling Machine acquisition, and the Daikin–Shin-Etsu–Hitachi–Tokyo Eco Recycle rare-earth magnet project would seem to belong to separate policy worlds. One concerns digital infrastructure, another industrial equipment and another material recovery.
Together, they point to an infrastructural challenge Japan must plan to surmount. Japan’s civilian industries and defense systems often depend on the same infrastructure, and when disruption occurs below the threshold of open conflict, Japan must be able to keep civilian functions working while restoring defense-relevant systems.
Gray-zone conflict is the setting Japan is more likely to face first. A subsea cable may be damaged without clear attribution, or a port or airport communications system may be disrupted by cyber operations.
Incidents like these cost time, money and manpower before officials can say whether the cause was accidental, criminal or coercive. As an archipelagic state, Japan cannot separate civilian infrastructure from defense readiness.
Tokyo has already acknowledged part of this challenge, but the structure remains incomplete. Japan’s National Security Strategy identifies gray-zone situations, cyberattacks on critical civilian infrastructure, and information warfare as pressures that blur the line between peacetime and contingency.
The Defense Buildup Program also treats the defense production and technology base as part of defense capability, while recognizing that advanced civilian technologies can shape future operations.
Recent fiscal year 2026 defense materials apply this logic to public infrastructure by designating selected airports and seaports for smoother Self-Defense Forces and Japan Coast Guard use, with road access to SDF bases added to the initiative from fiscal year 2025. These are important steps, but designation is only the beginning.
What Tokyo must decide now is which civilian systems are most exposed to gray-zone disruption and which failures would most quickly permeate both defense operations and civilian life. Japan cannot harden every port, cable, supplier, road, airport, cloud system and industrial firm equally.
In a gray-zone setting, priority should go to systems that must keep operating before Tokyo has all the information required for a decision. If an airport transport system is hacked, a port operating platform is compromised, or fuel logistics are interrupted, local authorities and private operators cannot freeze until attribution is clear.
The same access problem extends offshore. Japan is a major Indo-Pacific cable node. A CSIS report notes that Japan has more than 20 international submarine cable landing stations and around 30 active or announced international cable systems.
Those cables give Japan digital importance, but they also create a physical resilience problem. A damaged cable must be reached by a vessel, handled by trained crews, and restored through arrangements that often sit in private or commercial hands.
Japan has domestic strengths in this area. KDDI Cable Infinity works on construction and repair of domestic and international telecommunications submarine cables. A cable break may first appear as a commercial repair problem rather than a national security incident. That makes cable resilience part of Japan’s broader access challenge, rather than an isolated telecommunications issue.
Access and connectivity can allow Japan to keep moving during the early phase of disruption. Recovery then depends on the industrial capacity to repair what has been damaged.
A compromised logistics platform, delayed spare-part movement, restricted port access, or uncertainty around contractor responsibilities could create adverse operational effects without producing a clear military confrontation.
Japan’s intervention in MBK Partners’ proposed acquisition of Makino Milling Machine further illustrates a shift in how Tokyo views its broader defense apparatus. The case shows a more expansive view of defense-adjacent industry, where companies outside the traditional defense sector can still become relevant to national security.
METI lists machine tools and industrial robots among Japan’s specified critical products, alongside permanent magnets, aircraft parts, semiconductors, storage batteries, cloud programs, natural gas, critical minerals and ship parts. The firms and inputs that sustain defense capability often sit in ordinary industrial systems before they appear in security planning.
Material supply also matters because resilience also depends on what Japan can recover from its own civilian economy. The rare-earth magnet recycling project involving Daikin, Shin-Etsu Chemical, Hitachi, and Tokyo Eco Recycle provides a new pathway for material recovery.
These companies are developing a system to recover rare-earth magnets from commercial air-conditioner compressors and return them to magnet production. This further illustrates the connection between civilian commercial networks and defense-relevant industrial needs.
All of this demonstrates that Tokyo cannot treat gray-zone resilience as a traditional defense-industrial problem alone. A crisis below the threshold of open conflict may affect civilian infrastructure before it reaches the systems usually classified as defense. That makes ports, cables, repair capacity and material recovery part of the operational environment.
Tokyo has taken important steps within individual sectors, but gray-zone disruption will move across them. A holistic framework should build from these existing policy decisions and connect civilian infrastructure and commercial firms to Japan’s defense-industrial needs.
Two concrete steps would help. First, Japan should map defense-adjacent dependency chains for ambiguous disruption rather than clean wartime scenarios. The map should show where the same authorities, repair assets, emergency permissions, communications systems, and logistics providers would be needed by more than one system at the same time.
It should also identify which actions can begin before disruption attribution is clearly established. This could include protocols for rerouting cargo, maintaining backup communications, authorizing repair access for dual-use infrastructure and coordinating public-private action during disruption.
Second, public support for defense-adjacent industries should include crisis roles that can activate before blame is assigned. Firms across the defense-adjacent industrial base should know what they are expected to do when ordinary commercial systems are disrupted. Waiting for attribution allows operational disruption more time to spread. This should include two layers of preparation.
For the public, Japan should prepare clear guidance on how residents and businesses should respond during infrastructure disruption, where official information will come from, and which services may be temporarily rerouted or limited.
For industry and government, the protocol should be more operational: who contacts whom, who can authorize action, what can proceed under commercial procedures and when a disruption moves into a defense or interagency chain of command.
Japan should also treat this as a regional agenda because gray-zone disruption will not stop at Japan’s coastline. Submarine cables and other infrastructures that run through international space require pre-established repair processes before a crisis occurs.
Japan and its partners need standing arrangements that allow operators, vessels, and authorities to move quickly across jurisdictions without turning every scenario into a new diplomatic negotiation.
A particular focus should be on whether private industry can conduct repairs under commercial procedures or whether certain disruptions would require more traditional defense agreements between militaries.
Japan’s geography makes this work unavoidable. The most likely tests may come through ambiguous disruptions rather than open conflict. Tokyo’s ability to repair these disruptions quickly will determine whether gray-zone pressure remains manageable or spreads into a wider crisis.
Christian Cerne (christian@pacforum.org) is a research intern at Pacific Forum and a master’s candidate in International and Development Studies at the Geneva Graduate Institute. His work focuses on strategic resource diplomacy and economic security in the Asia-Pacific.
