Podcast Summary: "Cables submarinos: guerra híbrida en el fondo del mar"

Podcast: Un tema Al Día (elDiario.es)
Host: Juanlu Sánchez
Date: August 25, 2025
Guests:

• Carlos del Castillo (periodista especializado en tecnología, elDiario.es)
• Jesús Núñez (codirector del Instituto de Estudios sobre Conflictos y Acción Humanitaria)

1. Overview: Theme and Purpose

This episode explores the critical yet often invisible role of submarine data cables in global connectivity and how these infrastructures—vital for modern digital life—are vulnerable to sabotage and emerging as pivotal battlegrounds in what’s termed “hybrid warfare.” Through real-world incidents and expert analysis, the podcast delves into the technical, geopolitical, and security dimensions of disrupting undersea cables, with a focus on recent events in the Baltic Sea.

2. Key Discussion Points and Insights

The Vulnerability and Criticality of Submarine Cables

• Submarine Cable Incidents:
  • In November 2024, important cables between Finland and Germany, and between Lithuania and Sweden, were severed (01:24). Authorities labeled these as likely sabotage, linking to previous similar events in the Baltic.
• The Infrastructure in Numbers:
  • There are over 550 submarine fiber optic cables globally, covering more than 1.3 million kilometers (02:10).
• Misconceptions about Internet Infrastructure:
  • Despite the prevalence of WiFi, most internet traffic relies on physical submarine cables, not satellites or wireless tech.

How Cables Are Built, Protected, and Attacked

• Physical Structure and Protection:
  • Submarine cables contain optical fibers shielded by steel and plastics. Near coasts, some are buried to avoid accidental damage, but most lie exposed on the ocean floor where monitoring is nearly impossible (02:59).
  • Quote:

    "El cable... lleva la fibra óptica y está recubierto por acero y por plásticos... Luego, los cables no tienen una protección específica." — Carlos del Castillo (03:00)

• Ease of Sabotage:
  • A ship can cut a cable simply by dropping an anchor; deliberate action is hard to detect if ship transponders are off.
  • Quote:

    "Para un barco, colocarse encima del cable es tan fácil como desactivar su baliza..." — Carlos del Castillo (03:48)

Ownership and Control

• Mostly Private Ownership:
  • Traditionally laid by telecom companies, now increasingly owned or used by tech giants like Google, Meta, and Amazon. State involvement is very limited (04:41).
  • Quote:

    "En su mayoría son infraestructuras privadas... Ahora está habiendo mucha presencia también de los gigantes digitales." — Carlos del Castillo (04:43)

Redundancy and Internet Resilience

• Network Redundancy:
  • To prevent total outages, internet providers rely on redundancy—alternative cables/routes. However, significant local disruptions can occur if multiple cables are sabotaged (05:36).
  • Quote:

    "Normalmente el mundo digital trabaja sobre una medida de protección que se llama redundancia." — Carlos del Castillo (05:37)

The Strategic Map of Cables

• Geopolitical Patterns:
  • The cable network reflects historic and ongoing US technological dominance, but there is a current trend for more diverse routes, with Spain gaining new importance as a hub connecting Europe, Africa, and Latin America (06:43–08:32).
  • Quote:

    "Esa visualización es un ejemplo muy claro del poder que tiene Estados Unidos con Internet." — Carlos del Castillo (07:23)

Hybrid Warfare and Geopolitical Motivations

• Attribution Challenges:
  • In hybrid warfare, it's often difficult to prove responsibility, though suspicion frequently falls on Russia due to motives and past cyberactions (09:03).
  • Quote:

    "Precisamente una de las dificultades es poder determinar fehacientemente quién puede ser el actor..." — Jesús Núñez (09:04)

• Why Russia?:
  • Russia wishes to instill vulnerability in neighboring countries, particularly new NATO members like Finland and Sweden, using deniable actions ("la flota en la sombra") to avoid direct military conflict but exert pressure (11:16).
  • Quote:

    "En la medida en la que Rusia lo que busca es demostrarles su vulnerabilidad..." — Jesús Núñez (11:29)

• Hybrid War Defined:
  • Creating instability without crossing the threshold of open warfare — attacks designed to avoid triggering a direct military response (09:50).

Consequences and the Future of Global Internet

• Loss of Confidence in the Status Quo:
  • Repeated sabotage could weaken trust in a globally connected internet, particularly the current US-centric model (13:30).
  • Quote:

    "Va a haber una pérdida de confianza en cómo ha funcionado el Internet hasta ahora..." — Carlos del Castillo (13:31)

• Potential Balkanization:
  • Rising trend toward national or regional Internets, especially in authoritarian states like Russia and China. These countries aim for sovereign control, restricting external influence and, indirectly, free expression (15:30).
  • Quote:

    "Internet va hacia una balkanización. Hay países que quieren que Internet deje de ser tan global..." — Carlos del Castillo (14:05)

3. Notable Quotes and Memorable Moments

• On the fragility of cables:

  "Para un barco, colocarse encima del cable es tan fácil como desactivar su baliza e ir a la ubicación de un cable..." — Carlos del Castillo (03:48)

• On US digital dominance:

  "Esa visualización es un ejemplo muy claro del poder que tiene Estados Unidos con Internet. Es un ejemplo de esa colonización digital..." — Carlos del Castillo (07:23)

• Defining hybrid war:

  "Se trata de acciones que... buscan precisamente mantener un nivel de inestabilidad bajo control para no traspasar el umbral que pueda llevar a una escalada..." — Jesús Núñez (09:52)

• The risk of Internet fragmentation:

  "Internet va hacia una balkanización. Hay países que quieren que Internet deje de ser tan global como lo ha sido..." — Carlos del Castillo (14:05)

• On geostrategic pressure:

  "En la medida en la que Rusia lo que busca es demostrarles su vulnerabilidad... una escalada que puede ir derivando todavía acciones más directamente contra sus intereses..." — Jesús Núñez (11:29)

4. Timestamps for Important Segments

• [01:24] - Real-world cable sabotage cases in the Baltic Sea
• [02:09] - Global scale and importance of submarine cables
• [02:59] - Physical construction and vulnerabilities
• [04:41] - Ownership and control: from telecoms to tech giants
• [05:36] - Redundancy and its limits
• [06:43] - The geopolitical 'map' created by cable routes
• [08:48] - Introduction of Jesús Núñez; hybrid warfare analysis
• [09:50] - Hybrid warfare, attribution issues
• [11:16] - Russia's objectives and strategy
• [13:30] - Future risks: trust, geopolitical reshuffling, Internet fragmentation
• [15:30] - Balkanization and the authoritarian desire for a sovereign Internet

5. Takeaways

• Submarine cables, though invisible to most, are critical to modern life and vulnerable to both accidental and deliberate disruption.
• Recent incidents likely targeting European critical infrastructure highlight the move toward hybrid warfare, with states using sabotage to sow instability without triggering open conflict.
• The cable map mirrors global power relations, but new cable routes and increased fragmentation suggest the global Internet’s future may be more regionalized and contested.
• The ongoing shift — both technological (redundancy, new hubs) and political (balkanization, sovereignty over data) — will significantly shape how we communicate and who controls our flows of information.

This summary captures the depth and urgency of the episode, providing a roadmap for anyone seeking to understand why invisible fiber-optic cables are suddenly at the heart of big-power rivalry, and why their safety matters to all internet users.