Undersea Cables, Viral Threats, and the Fragile Backbone of the Internet: Iran, Sabotage, and What It Really Means, By Richard Miller (London)
In late March/early April 2026, as tensions between Iran, the US, Israel, and Gulf states boiled over into open conflict, a new nightmare scenario exploded across social media and news outlets: Iran was reportedly threatening to cut the undersea internet cables that snake through the Red Sea and the Strait of Hormuz. Posts claimed these cables carry 95% (sometimes 99%) of global internet traffic. The implication was apocalyptic — sever a few fibre-optic lines on the seafloor and watch banking, streaming, military comms, and supply chains grind to a halt worldwide.
One email circulating among observers noted there's "no ref" — no official, verifiable reference — that Tehran itself has made this threat. That's broadly correct. The claims trace back to unverified social-media posts, amplified by commentators and picked up by outlets in India and elsewhere. No Iranian government statement, no major intelligence confirmation. Iran-backed Houthis have floated similar ideas on their channels before, but the "Iran is about to unplug the world" narrative remains in the realm of viral rumour rather than confirmed policy.
Still, the story landed because it touches a real nerve: the global internet's hidden vulnerability. Even if this particular threat is exaggerated or deniable, the cables are exposed, sabotage is feasible in certain spots, and the consequences of deliberate (or even collateral) damage in a war zone are no joke. Let's unpack it.
The Hidden Arteries: Just How Much Traffic Do These Cables Carry?
Undersea fibre-optic cables — thin, garden-hose-sized bundles of glass strands sheathed in armour — are the physical internet. They handle well over 95% of all intercontinental data traffic. Satellites carry the rest, but they're slower, more expensive, and capacity-limited. A single modern cable can move terabits per second; together, the roughly 500 active submarine systems form the circulatory system of the digital economy.
Chokepoints matter. The Strait of Hormuz and the Red Sea are two of them. Cables there link Europe, Asia, Africa, and the Middle East. Disruptions here don't black out the planet, but they can slow traffic dramatically, force rerouting (which adds latency and cost), and hammer specific regions — including India, Europe, and Gulf data hubs. Recent history shows the risk: in 2024, Houthi-related incidents cut or damaged Red Sea cables, disrupting up to 25% of regional traffic in some cases. Repairs took months because the area became too dangerous for cable ships.
How Vulnerable Are They, Really?
Cables are surprisingly easy to damage in shallow water — and the Red Sea/Hormuz zones include plenty of shallows. Most accidental (and many suspected deliberate) cuts happen when a ship's anchor drags across the seabed or fishing trawlers snag them. In deeper ocean, they're harder to reach without specialised gear. But near shores or in straits, they're sitting ducks.
Recent Baltic Sea incidents (2024–2025) illustrate the pattern: suspected Russian or Chinese-linked vessels dragging anchors, severing cables in "grey zone" operations that are hard to attribute as acts of war. No missiles needed — just a commercial ship with a heavy anchor and plausible deniability.
Iran has advantages here. Its Revolutionary Guard operates swarms of fast boats and has influence over proxies. In a hot conflict, a "civilian" vessel or Houthi dhow dragging an anchor (or using simple dredging gear) could do the job without fingerprints. Landing stations on shore are even easier targets. The cables themselves aren't armoured against deliberate sabotage in every segment; burial helps in shallows, but it's not universal and can be dug up.
Caveats: Iran would almost certainly hurt itself. Many cables serve Iranian connectivity too, and the country relies on the same global network for oil exports, banking, and propaganda. Deliberate mass severance would be mutually assured disruption — more like economic suicide than precision strike. Experts note the real danger is often collateral: stray anchors from damaged tankers, mines, or naval manoeuvring in a war zone.
Is It Doable? Yes — in the right conditions.
Low-tech method: Anchor-dragging or grappling from a ship. Cheap, deniable, effective in <200m depths.
Higher-tech: Submarines or remotely operated vehicles (ROVs) for deeper cuts, but that's state-level and riskier.
Proxy play: Houthis or other allies do the dirty work while Tehran denies involvement.
It's not science fiction. Russia and China have been accused of similar hybrid tactics in European waters. Iran's naval posture in the Gulf already includes mining threats and vessel harassment. In a shooting war, turning the seabed into a no-go zone for repair ships is almost as damaging as cutting the cables themselves — outages last longer because no one can fix them.
That said, total global blackout is hype. Redundancy exists: traffic can reroute via other oceans (Atlantic, Pacific routes), and major providers have diverse landing points. But prolonged cuts in key corridors would spike latency, crash some services, and expose just how much of modern life rides on a few hundred fragile lines.
What Could Be Done to Protect Them?
Protection is imperfect but possible. Here's the realistic menu:
1.Redundancy and diversity: Build more cables on varied routes. Meta's 2Africa project and others aim for this, but war zones delay construction. Diversify landing points and encourage satellite/mesh backups (Starlink-style low-Earth orbit systems help, but can't yet replace terabit-scale fibre).
2.Physical hardening: Bury cables deeper in vulnerable shallows (where feasible and cost-effective). Use armoured sheathing and sensors that detect tampering or seismic activity in real time.
3.Surveillance and patrols: NATO-style operations (like Baltic Sentry) with drones, seabed sensors, and naval escorts for repair ships. In the Gulf/Red Sea, this would require de-escalation or international agreements — politically tough in conflict.
4.Legal and diplomatic norms: Treat deliberate cable sabotage as an act of war or cyber equivalent. The 1884 International Convention on the Protection of Submarine Cables is ancient and unenforced in practice. Update it for the hybrid era.
5.Rapid repair capacity: Stockpile cable ships and pre-position repair kits outside conflict zones. International consortia already do this, but war turns repair into a high-risk mission.
None of this is foolproof. The internet was never designed for great-power seabed warfare. Its resilience comes from distributed architecture, not fortified infrastructure.
Whether or not Iran ever issues an official "we will cut the cables" statement, the rumour itself is a warning. Modern conflict increasingly targets the invisible infrastructure we take for granted — pipelines, power lines, data cables. The internet's physical layer is surprisingly analogue: glass threads on the ocean floor, protected mostly by international norms and the assumption that no one would be crazy enough to yank them.
In an era of grey-zone aggression, that assumption is eroding. The real lesson isn't panic over one viral threat. It's that our digital world still rests on surprisingly vulnerable analogue3 foundations — and protecting them requires the same mix of engineering, diplomacy, and hard power that we apply to oil tankers or satellites.
The cables will probably keep working. But the next time a tanker drags an anchor in the wrong strait, or a "fishing boat" lingers too long, remember: the internet isn't ethereal. It's physical, it's fragile, and in the wrong hands, it can be interrupted — even if the world doesn't end when it is.
