The primary optical submarine cables connecting South Asia to global networks are SEA-ME-WE 4, FLAG, and the upcoming SEA-ME-WE 6.

SEA-ME-WE 4

The South East Asia–Middle East–Western Europe 4 (SEA-ME-WE 4) is a major optical fibre submarine cable system spanning approximately 18,800 kilometres. It links Singapore, Malaysia, Thailand, Bangladesh, India, Sri Lanka, Pakistan, the UAE, Saudi Arabia, Egypt, Italy, Tunisia, Algeria, and France, serving as a critical internet backbone between South Asia, Southeast Asia, the Middle East, and Europe. The system is divided into four segments with sixteen landing points and was completed in 2005 at a cost of around US$500 million. Segment 1, running 8,000 kilometres from Singapore to India, was built by Fujitsu, which also provided repeater equipment for Segment 4. SEA-ME-WE 4 has historically been a key conduit for internet traffic in the region, though it has experienced disruptions due to cable damage in the Mediterranean Sea affecting countries like India and Egypt .

FLAG (Fibre-optic Link Around the Globe)

The FLAG cable system is another major optical submarine network connecting India, Japan, the UK, and other locations along a 28,000-kilometre route. Operated by Global Cloud Xchange, FLAG provides high-capacity connectivity between Europe and Asia, using synchronous digital hierarchy technology and erbium-doped fibre amplifiers. It carries over 120,000 voice channels and was first placed into commercial service in 1997, making it one of the earliest high-capacity transcontinental cables serving South Asia .

SEA-ME-WE 6

The SEA-ME-WE 6 project is the latest addition to the region's submarine cable infrastructure, designed to enhance capacity and resilience. Construction was awarded to SubCom in 2022, following geopolitical competition between the US and China over cable contracts in Southeast Asia. SEA-ME-WE 6 will further strengthen connectivity between South Asia, Southeast Asia, the Middle East, and Europe, reflecting the strategic importance of subsea cables in global data traffic and regional digital infrastructure .

Strategic Importance

Submarine cables like SEA-ME-WE 4, FLAG, and SEA-ME-WE 6 are critical for South Asia's internet connectivity, carrying over 95% of global data traffic. They support commerce, communication, and digital services far more efficiently than satellite links. The region's reliance on these cables also makes it a focal point for geopolitical considerations, as control over cable routes can influence data flow and security . In summary, SEA-ME-WE 4 and FLAG remain the main operational optical cables for South Asia, while SEA-ME-WE 6 is set to expand capacity and resilience, ensuring the region remains well-connected to global networks.