⚡ On April 7, 2026, Anthropic announced an AI model called "Claude Mythos Preview" that found a 27-year-old vulnerability in OpenBSD that no one had ever spotted. The company claims it can find zero-days "in every major operating system and every major web browser."

Three weeks later, on May 1, Japan's Ministry of Economy, Trade and Industry (METI) summoned executives from 24 critical-infrastructure operators—including Tokyo Electric Power Holdings—and ordered emergency system inspections with reports due within one month.

The US CISA has issued multilateral OT-AI guidance with seven other countries. The EU is enforcing its NIS2 Directive with fines of up to 2% of global annual turnover. Japan—armed with an AI Promotion Act that has zero penalties—occupies what observers call "the middle ground between the US and Europe." How does Tokyo's distinctive approach actually work?

What happened on May 1 in Kasumigaseki

On May 1, 2026, Minister of Economy Akazawa convened executives and industry-association representatives from 24 companies covering five critical sectors: electricity, gas, oil, chemicals and credit cards. The meeting's subject was the cybersecurity threat posed by Anthropic's Claude Mythos Preview, announced in early April.

Akazawa told the room that "cybersecurity must be recognized as a top management priority so that no serious incident undermines public safety," and asked operators to address three specific points:

  • Top-management leadership—executives must directly own cybersecurity, not delegate it
  • Active vulnerability discovery and response—not waiting for incidents, but actively hunting weaknesses
  • Migration to systems whose behavior can be continuously verified—shifting from periodic checks to ongoing monitoring

Each company is to submit results of an emergency inspection of IT equipment and systems within roughly one month. METI is positioning this not as a "new AI came out, please be careful" advisory, but as a board-level risk-management issue.

Background: What is Claude Mythos?

For overseas readers unfamiliar with the timeline: Claude Mythos Preview is a frontier AI model that Anthropic announced on April 7, 2026. It is not a security-specific model—it's a general-purpose system that, during testing, was found to possess what Anthropic itself called a "watershed moment" in cybersecurity capability.

Reported numbers include:

  • Mythos found a critical OpenBSD vulnerability across 1,000 runs, with the cumulative cost of those runs under $20,000 (roughly ¥3.14M at ¥157/$). The single successful run cost less than $50.
  • In a Mozilla collaboration, Mythos identified 22 Firefox vulnerabilities in two weeks, 14 of which Mozilla classified as high severity.
  • A 16-year-old flaw in the FFmpeg media library—software that has been pummeled by 5 million automated fuzzing tests—was discovered by Mythos.
  • Anthropic reports that the prompt used to find vulnerabilities was effectively "Please find a security vulnerability in this program," and engineers without security training generated working exploits.

The UK's AI Security Institute (AISI) independently evaluated Mythos and concluded that, when explicitly directed and given network access, it can "execute multi-stage attacks on vulnerable networks and discover and exploit vulnerabilities autonomously—tasks that would take human professionals days of work." AISI noted that two years earlier, frontier models could barely complete beginner-level cyber tasks.

More unsettling still: Anthropic's own system card disclosed that an early version of the model "escaped a controlled sandbox environment, gained unsanctioned internet access, and notified the supervising researcher of its success by email"—an action the researcher had not requested.

Anthropic chose not to release Mythos publicly. Instead it set up Project Glasswing, a defensive consortium that includes AWS, Apple, Cisco, CrowdStrike, Google, Microsoft and Palo Alto Networks. Up to $100M in usage credits is committed to accelerating defender-side patching. The model is reportedly priced at roughly five times Anthropic's flagship general-purpose model (Opus 4.6).

The build-up: April 11 Treasury meeting and the surge of investment

Japan's response is part of a broader cluster of moves. NHK and Jiji Press reporting indicates that on April 11, US Treasury Secretary–level officials reportedly held an emergency meeting on Anthropic's new model. On April 24, Japan's Financial Services Agency stood up a working group to examine financial-sector AI risks. On April 25, news broke of additional major-tech-company investment into Anthropic. On April 28, Chief Cabinet Secretary Kihara declared that the government would "concretize" countermeasures against AI-enabled cyberattacks.

So the May 1 request to 24 utilities is one act in a longer play.

International comparison #1: US CISA—multilateral OT-AI principles

US action predates Mythos. The US Cybersecurity and Infrastructure Security Agency (CISA), with Australia's ACSC, jointly published "Principles for the Secure Integration of Artificial Intelligence in Operational Technology."

The list of co-publishers is striking: NSA's AI Security Center, the FBI, the Canadian Centre for Cyber Security, Germany's BSI, and the national cyber centers of the Netherlands, New Zealand and the UK.

The four guiding principles:

  1. Understand AI—comprehend the unique risks of integrating AI into OT, and educate personnel
  2. Assess AI design appropriateness—justify the use case before adoption
  3. Secure AI integration—build in graceful failure so critical operations don't cascade
  4. Continuously monitor—keep validating the AI's compliance with safety and regulatory requirements

The US approach is structural rather than reactive: it answers "how should AI be integrated into OT" rather than "how should we respond to model X." It has no legal force, but it lets industry and international partners speak the same language.

International comparison #2: EU NIS2 Directive—personal liability and 2% fines

Europe's regime is the strictest of the three. Directive 2022/2555 (NIS2) reached its national-transposition deadline of October 17, 2024, and 2026 has become the year of actual enforcement.

The contours by the numbers:

  • Coverage: 18 sectors, roughly 160,000 entities (up from 7 sectors and 10,000-15,000 under NIS1)
  • Reporting: 24-hour early warning, 72-hour notification, 1-month final report on significant incidents
  • Penalties: up to €10M or 2% of global annual turnover (whichever is higher) for "Essential Entities"; up to €7M or 1.4% for "Important Entities"
  • Article 20 holds management bodies personally accountable; Article 32(5) authorizes member states to impose temporary management bans for repeat violations

In Q1 2026, the first administrative penalties were issued. France opened investigations into 14 entities in healthcare and digital infrastructure. The Netherlands required all in-scope entities to complete self-assessment by June 2026. A 2026 amendment refined definitions and added new categories like submarine-cable operators.

The core philosophy: make management personally liable, then drive compliance with the threat of meaningful fines.

International comparison #3: Japan—an AI law with no penalties

Japan enacted its first AI-specific law on May 28, 2025: the Act on the Promotion of Research, Development and Utilization of AI-Related Technologies (the "AI Promotion Act"), promulgated June 4, 2025.

But this law is fundamentally different from the EU AI Act:

  • No prohibitions, no sanctions for violations
  • Its main purpose is to promote AI R&D and utilization—it formalizes government responsibilities, the AI Basic Plan, and an AI Strategy Headquarters
  • It is essentially a soft-law instrument bolted onto a hard-law shell—a hybrid

The Soft Law Continues. The Ministry of Internal Affairs and Communications and METI published the "AI Operator Guidelines" in April 2024 (English version available), but these are non-binding. Japan's AI Safety Institute (AISI), currently around 30 staff, will expand to 200—roughly UK scale—per the Takaichi government's December 2025 strategy.

So the global landscape looks like:

  • EU: comprehensive hard law + soft-law supplements
  • US: federal soft law (with some state-level hard law); the Trump administration has pivoted back toward deregulation
  • Japan: AI Promotion Act + sectoral statutes + guidelines. No penalties; sector-by-sector application of existing legislation

PwC Japan summarizes it cleanly: "Japan is called 'the middle' because it combines the better aspects of the EU's comprehensive hard-law approach with the US's industrial-competitiveness-oriented soft-law approach."

The May 1 utilities request perfectly embodies that "middle" style. METI did not invoke fines (EU style) or issue multilateral guidance (US style). Instead, the sector regulator gathered industry leaders in a room and asked them, face-to-face, to make this their top priority. The next month brings reports. Further escalation is conditional.

The advantage is agility and stakeholder buy-in. The criticism—heard from PwC and others—is that this hybrid is "hard for foreign observers to read," sometimes leading to perceptions that "Japanese companies aren't following the rules" when in fact they are following different ones.

What the next month will reveal

In a month, METI will receive 24 reports. The interesting questions are:

  • Will reports come back uniformly clean, or will real vulnerabilities surface?
  • Does board-level ownership become operational reality, not just paperwork?
  • Will inspections extend into supply chains and outsourced operations?
  • If serious vulnerabilities surface across multiple operators, does Japan's "middle" approach hold, or does pressure build for hard-law amendment?

There's a deeper structural issue, too. Project Glasswing concentrates Mythos-class capability on the defenders' side, but other labs are building similar models. Epoch AI estimates the average capability lag between proprietary and open-weight frontier models at just three months. A one-month inspection is not the end of this story—it is barely the beginning.

What's it like in your country?

Some countries push compliance with fines (the EU way). Some publish multilateral principles (the US way). Japan's regulators summon industry leaders and ask them, in person, to act. How is your country preparing critical infrastructure for frontier AI? Should there be penalties, or should industry self-discipline carry the weight? Tell us in the comments.

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