Written by Wu Shang-Su.
Since created by the French New School in the 19th Century, sea denial has been seen as an asymmetrical strategy for a weak coastal state to counter a superior counterpart. Unlike small European states relying on NATO, or other developing countries in other continents having limited resources to build up navies, South East Asian countries have broad maritime concerns, such as the South China Sea, and certain levels of national resources to invest in navies. However, they have no comprehensive regional security framework to depend on. Thus, sea denial a strategy for South East Asian countries to counter the clear and present danger of Chinese sea power. However, the operational environment, technological factors and lack of flexibility make sea denial insufficient for the comprehensive maritime challenges facing the region.
Maritime patrol aircraft, mainly powered by multi-turbo prop engines, could have capacity for anti-ship missiles and surveillance facilities, but their low speed and poor mobility makes them vulnerable to missile attacks.
The sea denial strategy refers to denying an enemy’s maritime activities in a certain space; but the main targets are concentrated on surface vessels for their significance in trade and force projection. After more than a century, German and Soviet practices have enriched the sea denial strategy in three dimensions: underwater, surface and air. Submarines have been the iconic method of sea denial since their invention, and their deterrence role is well known based on several real cases, such as the Falkland War.
However, today, a credible underwater fleet is more difficult to build up, because of the increasingly sophisticated characteristics of modern submarines, which require a range of skills, infrastructure and logistical support. Consequently, the financial costs of procurement, operation and maintenance impede coastal states from establishing a considerable underwater fleet and further reduce the number of serviceable boats. Moreover, most coastal states are unlikely to have several major naval bases to maintain and resupply submarines. Therefore, a single strike on such a facility could paralyse, if not neutralise, a state’s submarine capability. Despite several procurements by South East Asian countries, the current largest regional fleet, Vietnam’s, comprises six boats, suggesting a narrow margin to bear loss and a limited operational capacity.
Fast attack craft (FAC) with anti-ship missiles have been the cheapest platform for sea denial after replacing their predecessor: torpedo boats. However, their limited over-horizon surveillance capability and open sea operational environment undermine their combat efficiency. Unlike in the 1960s and 1970s, FACs’ operational environment for sea denial is no longer the narrow coastal waters, but the more extended areas, such as the Exclusive Economic Zones (EEZs). Such sea areas that are crucial for many South East Asian navies. In order to maintain mobility, Fast Attack Craft are unlikely to carry out manned aerial operations for surveillance. Although small drones present a solution, their capability as searching vessels on the broad open oceans has not been comprehensively proven.
Despite extending ranges of anti-ship missiles, Fast Attack Craft usually have limited detection capabilities beyond the horizon, which leave them dependent on other surveillance means, such as aircraft, or attacking with less information. For regional countries, it is a great challenge to operate a functional wing for maritime reconnaissance and operational networks, not to mention survivability in the face of hostile air superiority or electronic warfare. If the Fast Attack Crafts’ defence area is merely territorial waters, then coastal terrains such as bays and caves provide protection. Operating in an open sea area makes them more vulnerable to radar detection. Despite some stealth designs, it is not easy to be invisible in open sea areas in the face of modern surveillance capabilities. Restricted by space, tonnage and costs, Fast Attack Crafts usually fall short in self-defence capability.
Maritime patrol aircraft and multi-function fighters are the most likely aerial platforms for sea denial strikes, especially in the open seas, but they face various issues. Maritime patrol aircraft, mainly powered by multi-turbo prop engines, could have capacity for anti-ship missiles and surveillance facilities, but their low speed and poor mobility makes them vulnerable to missile attacks. In contrast, multi-purpose fighters with high speed and mobility would be more useful for sea denial during wartime. However, without proper surface-search radars, the fighters may not efficiently find targets. Furthermore, because they are expensive, whether int arms of procurement, training and maintenance, the serviceable number of fighters is often limited. Operationally, they would be assigned to air defence or other missions rather than sea denial. Organisationally, fighters are mostly operated by an air force rather than a navy, so that their training focuses mainly on air-to-air combat and other conventional tactics, rather than striking surface vessels.
Finally, the sea denial strategy is conditioned for wartime and its assets would not perform well in peace time, which is the current situation South East Asian countries face. Obviously, submarines and fighters are not suitable platforms to respond to “post-modern” missions, such as law enforcement on seas or search and rescue, due to operational and economic constraints. Fast Attack Crafts can reach and stay at a certain maritime location, but their relatively small displacement means that they have lower capacity to endure rough sea conditions than larger vessels. Moreover, due to their relatively lower tonnage they are vulnerable to ramming. Thus, building offshore patrol vessels would be more efficient than Fast Attack Crafts for peace time scenarios.
Based on the factors mentioned above, South East Asian countries do not fully embrace sea denial but acquire major surface combatants, which are not suitable for sea denial due to their relatively large sizes. The regional navies also introduce a wide range of ships – one end of the spectrum being frigates, oriented for conventional warfare and aimed at regional sea control, and at the other end, poorly armed offshore patrol vessels for post-modern missions during peacetime.
In other words, South East Asian countries attempt to include elements from sea control and the post-modern strategies depending on individual needs. The hybrid practice in the region demonstrates not only the insufficiency of the sea denial strategy for non-allied coastal states in the current environment, but also the possibility of forming a new naval strategy through the evolution of various practices.
Dr Wu Shang-Su is a Research Fellow in the Military Studies Programme of the S. Rajaratnam School of International Studies (RSIS), Nanyang Technological University, Singapore. Image credit: CC by US 7th Fleet/Flickr.