Japan lays the groundwork for submarine cable resilience

2026.06.25

By Anna Oriishi, Institute for Information and Communications Policy

Beneath the oceans, out of sight and mostly out of mind, lies the infrastructure that keeps messages sending, videos streaming and AI tools answering in real time. Fiber-optic cables carry nearly all the world’s data between continents. When one is damaged — by an anchor, an earthquake or something more deliberate — traffic must keep moving. That resilience is what keeps digital life, and AI, running smoothly.

Among the 17 strategic sectors in the Takaichi Cabinet’s growth strategy, “information and communications” includes measures to strengthen digital infrastructure, notably by promoting geographic diversification of international submarine cable landing points across Japan. Following a series of incidents that resulted in submarine cable damage in the Baltic Sea and near Taiwan, there is growing international recognition that submarine cables are not only foundational infrastructure for the digital economy but also critical assets for national security.

Against that backdrop, Japan launched a “Study Group on the Protection of International Submarine Cables” in November 2025. Ensuring cable security is now widely seen as a national priority, underpinning not only wartime resilience but also the stability of social and economic systems in peacetime.

Historically, the global submarine telegraph network was dominated by the United Kingdom, with cable deployment closely tied to colonial governance and military positioning under strong state leadership. Today’s fiber-optic cable networks, by contrast, have largely been developed through joint investment by private companies across multiple countries.

That balance is shifting. In recent years, hyperscale technology companies such as Google and Meta have increasingly financed, owned and operated submarine cables on their own. These firms have the capital to build infrastructure capable of supporting the massive data flows generated by global cloud services. Coordination between hyperscalers and the U.S. government to expand submarine cable networks has also become more visible.

As markets evolve and state involvement grows, policymakers face a new reality: Whether a country has its own hyperscalers may increasingly shape its strategic options.

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An “intercontinental” vision

In the system supplier market — responsible for designing and building submarine cables — Chinese firms have entered a sector long dominated by companies from Japan, the United States and Europe, steadily increasing their share of contracts. In response, Washington has supported hyperscaler-backed cable projects in cooperation with allies and partners. Since the Biden administration, such initiatives have frequently appeared joint statements following bilateral summits.

One example is Google’s Pacific Connect initiative, which refers to a series of cable projects across the Pacific since 2023, supported by U.S. financial and diplomatic engagement with landing countries.

At the October 2023 U.S.-Australia summit, leaders highlighted investment in the South Pacific Connect. Similarly, the April 2024 U.S.-Japan summit referenced Google’s roughly $1 billion investment in the North Pacific Connect. Japanese system suppliers are also involved, illustrating how trilateral cooperation among Japan, the United States and Australia is facilitating route diversification in response to geopolitical risk.

Hyperscaler-led projects have continued to feature in summit diplomacy under the Trump administration. At the February 2025 U.S.-India summit, leaders welcomed Meta’s investment in a submarine cable spanning five continents and roughly 50,000 kilometers (31,000 miles). This likely refers to the Waterworth cable, expected to be one of the longest systems in the world, connecting the United States, India, Brazil and South Africa.

Notably, the project represents Meta’s first privately owned submarine cable of this scale. In the joint statement, India signaled its intention to invest in cable maintenance, repair and financing across the Indian Ocean, emphasizing the use of trusted vendors.

A “sea-basin” strategy

Hyperscaler-led projects, however, do not always align with regional needs. The Waterworth cable, for example, is designed to bypass Europe entirely. While U.S. firms are building large intercontinental systems, they have shown less interest in regional cables linking European Union member states.

In response, the EU has pursued a distinct strategy grounded in regional cooperation. Recognizing that Europe lacks hyperscalers and that its firms face investment constraints, policymakers have adopted what can be described as a “sea-basin” approach to resilience.

Through public funding, the EU has supported cable deployment led by European firms and member states. Following the release of the EU Action Plan on Cable Security in February 2025, policymakers reassessed where public investment should be prioritized.

An EU report published this February mapped cable infrastructure across 11 maritime regions, identifying gaps where additional routes or alternative connections are needed.

The EU is also exploring a hub-based model to improve threat detection. Under this concept, member states would establish regional cable hubs, beginning in the Baltic Sea and expanding elsewhere. These hubs would integrate monitoring systems, pool operational data and use AI-driven analysis to provide near real-time situational awareness and faster response to disruptions.

In short, the EU strategy combines public investment with regional coordination — not only to expand infrastructure but also to strengthen monitoring and operational resilience.

An “island hub” model

Japan, which lacks domestic hyperscalers and does not benefit from the EU’s level of regional integration, must chart its own course. In this regard, the United Kingdom offers a useful comparison.

Like Japan, the U.K. is an island nation that has long served as a major landing hub for international cables. But its position is under pressure.

Japan has historically connected the United States and Asia along the shortest trans-Pacific routes. Yet in recent years, hyperscaler-funded cables have begun bypassing Japan — a trend sometimes described as “Japan-passing.”

A similar shift is underway in the U.K. While it remains a key landing point for trans-Atlantic cables, newer high-capacity systems have landed directly in EU member states, bypassing the U.K. Analysts note that roughly 75% of trans-Atlantic cable capacity between the United States and the United Kingdom is concentrated in just two hyperscaler-financed systems.

In response, the U.K. government is moving beyond a focus on simply adding cables or diversifying routes. Policy discussions now emphasize operational resilience — including available capacity during crises and the ability to reroute traffic quickly.

Following a parliamentary report, the government announced new measures in December 2025, including a review of regulatory frameworks. These efforts aim to assess how dependent critical sectors are on submarine cables, evaluate the potential impact of disruptions and strengthen contingency planning.

Lawmakers have also questioned policies focused solely on increasing the number of cables. More landing points alone, they argue, do not guarantee resilience.

The next phase

Strengthening submarine cable resilience can no longer be separated from the role of hyperscalers. The United States, home to these firms, can leverage their investments to promote redundancy and route diversification. The EU, lacking such companies, has responded with public funding and regional coordination. The U.K., as an Atlantic hub, is shifting toward operational readiness and crisis management.

Japan must now consider how to respond within its own strategic context. Drawing lessons from these international developments, Japan should leverage its geographic position as a hub in the Asia-Pacific while formulating the next stage of submarine cable resilience policy.

Ultimately, policymakers must decide how submarine cable resilience fits into national strategy, taking into account market dynamics, technological capabilities, geographic realities and international partnerships.

The question is no longer whether submarine cable resilience matters. It is how to secure it in an era when the global economy — and the future of AI — depends on it.

(Photo Credit: Getty Images)

[Note] This article was posted to the Japan Times on June 24, 2026:

https://www.japantimes.co.jp/commentary/2026/06/24/japan/japans-submarine-cable-resilience/

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