Challenges to Submarine Cable Connectivity in Southeast Asia and the Implications for Regional States

By Jeslyn Tan

Researcher, Centre for Maritime Security & Diplomacy (MSD), Maritime Institute of Malaysia (MIMA)

The fibre optic cables laid on the world’s seafloors have become more indispensable in the digital era when data is viewed as the “new oil”. There are now 552 submarine cables in service or under construction across the globe, spanning about 1.4 million kilometres (km) and transmitting over 95 per cent of global data traffic. Submarine cable connectivity is vital for the development of countries as it underpins their digital communications in finance and commerce, air and sea navigations, defence, as well as diplomacy. These cables are especially important in Southeast Asia which hosts many emerging economies with surging bandwidth demand. Malaysia recorded a peak in internet bandwidth demand in December 2022 at 1.9 terabytes per second (Tbps), indicating the increasing importance of submarine cables to the country’s digital economic growth. However, cable connectivity in Southeast Asia is vulnerable to challenges such as damage caused by human activities at sea and the South China Sea disputes, which will have implications for regional states.

Maritime activities like fishing, anchoring, and sand dredging pose great threats to submarine cables, particularly in Southeast Asia’s busy chokepoints. In June 2018, a submarine cable owned by Indonesia’s largest telecommunication provider PT Triasmita was unintentionally damaged by a Singapore-flagged vessel when anchoring off the coast of Riau Islands, Indonesia, which connect the Straits of Malacca and Singapore to the South China Sea. There was also a loss of internet service between Satun, Thailand and Kuala Perlis, Malaysia for several days after a submarine cable linking both places was damaged due to dredging activities of a Malaysian company, which led to one of the first submarine cable court cases in Malaysia named Thai Long Distance Telecommunication Co. Ltd. & Others v Malaysian Maritime Dredging Corporation Sdn. Bhd. [2010] MLJU 1893.

Additionally, submarine cables are prone to intentional damage such as cable theft. The most significant cable theft occurred in Vietnam in 2007, when fishermen removed 98 km of the TVH cable and 79 km of the APCN cable from the country’s Exclusive Economic Zone (EEZ), along with the vital optical amplifiers, to be sold as scrap. This theft almost cut off Vietnam from international communication. In a region with many foreign trade-dependent economies, submarine cables are critical infrastructure. Nonetheless, scholars have pointed out the inadequacies of the existing international legal regime to protect submarine cables from intentional theft or terrorist acts in maritime zones beyond state sovereignty.

The South China Sea disputes have posed challenges to submarine cable connectivity in Southeast Asia as approval for cable installations and maintenance in the disputed waters must first be obtained from all claimant states, including China, which can be time-consuming. Beijing has reportedly obstructed the construction of the Southeast Asia-Japan 2 (SJC2) cable system that passes through Hong Kong and the South China Sea for more than a year by delaying the approval process and imposing stringent restrictions on the permit. As a result, submarine cable contractors are circumventing the South China Sea in order to avoid the financial loss incurred due to approval delays in the contested waterway. The South China Sea offers the shortest possible route linking Southeast Asia to the more developed Northeast Asia. Bypassing it will impede the technological advancements and economic development that drive the emerging digital economies of Southeast Asian states, as higher costs and longer periods of time are needed for cable construction and maintenance along new longer routes.

Submarine cables are critical infrastructure that should not be a tool for geopolitical competition due to their importance to regional digital connectivity. The International Cable Protection Committee (ICPC) recommends that states set aside overlapping maritime boundary claims and remain unprejudiced and neutral in order to facilitate cable installation and repair in contested maritime zones. Although not legally binding, ICPC provides useful guidelines for states and submarine cable operators to protect the undersea critical infrastructure.

It is important to have more comprehensive international laws and guidelines to govern submarine cables from vendor selection to cable installation and maintenance as well as protect the critical infrastructure from damage caused by human activities at sea. The International Maritime Organization (IMO) as the authority responsible for the safety and security of global shipping assumes a vital role in protecting submarine cables by designating no-anchorage areas such as in the Traffic Separation Scheme (TSS) of the Straits of Malacca and Singapore through a Safety Circular issued in 2009 or by reviewing the existing international regulations like the International Regulations for Preventing Collisions at Sea 1972 (COLREGs) with respect to submarine cable protection.

Submarine cables are crucial for the prosperity and security of all states and therefore cooperation on subsea initiatives is imperative for greater regional digital connectivity. The discussions on strengthening international submarine cable governance and partnerships could take place under the leadership of Southeast Asian states through the security mechanisms of ASEAN.


* This article is part of the “Blue Security” project led by La Trobe Asia, University of Western Australia Defence and Security Institute, Griffith Asia Institute, UNSW Canberra and the Asia-Pacific Development, Diplomacy and Defence Dialogue (AP4D). Views expressed are solely of its author/s and not representative of the Maritime Exchange, the Australian Government, or any collaboration partner country government.

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