Could the world’s most vital internet veins be cut in minutes? The events of the Red Sea this week indicate that yes, they might. Several major undersea fiber-optic cables SMW4, the India–Middle East–Western Europe (IMEWE), and the FALCON GCX were severed off the coast of Jeddah, Saudi Arabia, breaking connectivity throughout parts of Asia and the Middle East. The outage lowered internet speeds in nations ranging from Pakistan to Kuwait, with Microsoft threatening that the Mideast “may experience increased latency due to undersea fiber cuts in the Red Sea,” though traffic bypassing the region remained unaffected.
Undersea cables are the silent backbone of global communications, transmitting over 95 percent of intercontinental data. These contain several layers polyethylene insulation, steel armor, copper conductors, and a hair-thin core of glass fibers carrying terabits of data per second as pulses of light. These are especially at risk of damage from ship anchors, fishing trawls, or sabotage in shallow seas such as the Red Sea. The SMW4 and IMEWE systems, operated by Tata Communications and a consortium led by Alcatel Submarine Networks respectively, are high-capacity routes linking South Asia, the Gulf, and Europe. The FALCON GCX, owned by Global Cloud Xchange, connects the Gulf states to Egypt and beyond.
The reason behind the most recent cuts is not yet clear. Yemen’s Houthi rebels, who have been attacking Red Sea shipping with missiles and drones since late 2023, have long been suspected of plotting to attack subsea cables. Yemen’s government-in-exile accused them of such a plan in early 2024, but the Houthis have routinely denied attacking the lines. On Sunday, the Houthis’ al-Masirah channel conceded the outages, using data from NetBlocks, but made no assertion of responsibility.
Technically, it takes a slow and delicate operation to fix a ruptured subsea cable. Cable repair ships, which are specially equipped, initially identify the break using time-domain reflectometry, a measurement of the delay in light pulses reflected off the fault. With the location found, remotely operated vehicles or grapnels hook up the cable from the ocean floor typically hundreds or thousands of meters below so that engineers can insert a new section by splicing. The fixed cable is then set down with great care on the seabed, the joint covered by steel casing. In busy seaways such as the Red Sea, where depths may be more than 2,000 meters and traffic volumes are dense, these exercises may last weeks, particularly if several systems are damaged at once.
The strategic significance of the Red Sea to internet infrastructure worldwide cannot be underestimated. It is one of the planet’s smallest chokepoints for subsea cable, piping dozens of systems between the Indian Ocean and the Mediterranean. Disruption here makes data go around the longer routes for instance, around the Cape of Good Hope adding latency and threatening congestion along alternative routes. Based on telecom monitoring reports, the outages already have resulted in quantifiable slowdowns in India and Pakistan, even with redundant routing.
The susceptibility of these networks has been known to engineers and security experts for years. Although cables are surveilled by network operations centers for signal loss, physical security is more difficult to maintain. Some operators use seabed mapping and automatic identification system (AIS) monitoring to identify ships anchoring close to cable routes, but where conflicts are present, these efforts can prove inadequate. Geopolitical instability in the Red Sea where Iranian-allied Houthis can use naval mines, unmanned surface vessels, and drone-carrying explosives adds to the threat.
The event highlights a rising threat to worldwide connectivity: the convergence of high-value, high-risk infrastructure with live areas of conflict. With more data traffic from finance transactions to cloud services riding on these fiber highways, the engineering and geo-political value of maintaining them has never been greater.
