Iran threatens to cut undersea internet cables if war resumes, what it means for India

Iran is threatening to damage undersea internet cables in the Gulf if war with the US and Israel resumes. But what happens if these cables are cut? Could India's internet, IT companies and online services be affected? We explain.

In Short

• Iran reportedly plans to target seven undersea internet cables if war resumes
• Damage to Gulf cable routes could disrupt India's international internet connectivity
• UPI will not get impacted in India 

Imagine opening WhatsApp one morning and finding that your messages are taking forever to send. You open X (formerly Twitter), but the feed refuses to refresh. Instagram is struggling to load, Google searches are taking longer than usual, and your video calls keep buffering. You try refreshing the internet and restarting your phone, but nothing seems to help. At first this might seem like a problem with your phone or internet provider. But what if it is happening thousands of kilometres away, deep below the sea near Iran?

That may sound far-fetched, but it is a possibility if Iran follows through on its latest threat to target undersea internet cables in the Persian Gulf if war with the US and Israel resumes. Two senior Iranian security officials told Reuters that Tehran has drawn up plans to attack these cables and could even prevent repair work, potentially prolonging disruptions.

And if that happens, the impact may not be limited to countries in the Gulf. India, too, relies on some of these undersea cable networks to stay connected to the rest of the world. So, while damage to these undersea cables does not mean Instagram or Google will suddenly stop working in India, it could disrupt international internet connectivity and affect how Indians access online services.

The web of undersea internet cables that connects the world

The Strait of Hormuz is usually in the news because of oil. But oil is not the only thing moving through this region. The narrow waterway is also an important route for undersea internet cables, which carry data between countries and keep much of the world's digital economy connected.

Think of these cables as fibre-optic highways running along the ocean floor. They carry everything from WhatsApp messages and video calls to emails, social media updates and online banking transactions, keeping countries connected around the clock. In fact, around 99 per cent of international data traffic travels through submarine cables.

And some of these cables run through the Strait of Hormuz. According to TeleGeography, less than 1 per cent of global international bandwidth passes through this waterway.

To put that into perspective, six active submarine cable systems run beneath the Strait: 2Africa, AAE-1, FALCON, Gulf Bridge International, Tata TGN-Gulf and OMRAN/EPEG. Two more, FIG and SEA-ME-WE 6, are under construction and expected to be ready in 2027. Together, these networks connect Gulf countries with parts of Asia, Africa and Europe.

Now, two Iranian security officials have told Reuters that Tehran has drawn up plans to attack these cables if the US and Israel resume military strikes. One of them also warned that Iran could prevent repair work, potentially keeping the networks disrupted for longer.

A disruption to these cables may halt the internet connectivity across the globe. But for Gulf countries and others that rely on these routes, the impact could be more significant. And India is among the countries that could feel the effects.

How is India's internet connected to these undersea cables?

India's internet depends on several submarine cables that come ashore at landing stations, including those in Mumbai and Chennai. These cables carry data between India and other countries, including those in the Gulf, Europe and beyond.

In an earlier India Today OSINT investigation, the report identified seven major submarine cable systems passing through or around the Strait of Hormuz, the same number Iran’s Revolutionary Guards have cited. At least four of them have links to Indian landing stations. Three of these are already live: FALCON, Gulf Bridge International (GBI) and AAE-1. Communications Today lists all three among the Hormuz-linked systems that land in India through Mumbai and Chennai. The fourth, SeaMeWe-6, has already been landed in Mumbai and Chennai by Bharti Airtel, but it is not yet in service and is due in 2027. Both Airtel and Reliance Jio have stakes in some of these networks: Airtel is part of the SeaMeWe-6 consortium, while Jio is a member of the AAE-1 consortium.

So, if Iran follows through on its threat and damages these cables, India's international internet connections could come under pressure. An Economic Times report earlier this year estimated that around a third of India's westbound data traffic passes through the Hormuz corridor. If Iran damages the cables, the telecom operators would then have to find other routes to move data between India and the rest of the world. One possible alternative is to redirect some traffic through networks connected to Singapore.

Affect internet users and businesses in India?

But re-routing will not bring things back to normal.

Think of it like a busy highway suddenly shutting down. Cars can take another road, but if everyone starts using the same alternative route, traffic slows down. The same thing can happen with internet data.

If telecom operators have to reroute large amounts of traffic through alternative cables, connections to overseas websites and servers could become slower. This is because data may have to travel a longer distance to reach its destination. It could also increase latency– the time taken for data to travel from one point to another.

For everyday users, this could mean slower international websites, lag during video calls, buffering while accessing overseas services or delays when using apps that rely on servers outside India.

It does not necessarily mean your entire internet connection will stop working, but there will be load on the connectivity.

Meanwhile, there could be a bigger impact on businesses that depend on international connectivity.

Banks and financial institutions, for instance, use these networks to communicate with overseas systems and process cross-border transactions. Disruptions could affect some international banking operations.

No impact on UPI

That said, everyday UPI payments are unlikely to be impacted. UPI or Unified Payments Interface in India runs on countries' domestic banking and payment infrastructure and does not depend entirely on undersea cables connecting India to other countries.

However, some international banking operations and cross-border transactions could face delays if these cable networks are disrupted.

India's IT and outsourcing companies could also face disruptions. They rely on stable internet connections to work with clients in the US, Europe and the Gulf. Slower connections could affect meetings, data transfers and everyday operations.

Rerouting data could also become more expensive, as telecom companies may have to pay more to use alternative cable routes.

So, while Iran's threat does not mean India's internet is about to go dark. But it could significantly impact country's digital economy which depends on infrastructure running thousands of kilometres beneath the sea.

- Ends