President Donald Trump's recent revelation about a United States Navy submarine's presence off Korea, during his phone conversation with his Philippine counterpart last month, provoked an interesting debate about submarine operations. Some were concerned whether such disclosure would have endangered crew safety, whereas others argued against making a mountain out of a molehill. In fact, the US Navy regularly publicises, with a certain degree of detail, its submarine activities worldwide.
However, similar levels of transparency are not always forthcoming for most of the Asia-Pacific's submarine operators, except for Australia and Japan, whose submarines made well-publicised visits to regional ports. By and large, the region's undersea community remains cloaked under a tight veil of secrecy - well romanticised by submarine campaigns during the world wars, and the post-1945 US-Soviet undersea cat-and-mouse games.
The "Silent Service" - as the submarine community is commonly referred to as - would continue to capture public imagination, especially in the Asia-Pacific, which has seen a persistent, ongoing spate of naval modernisation processes. By 2030, more than 250 submarines are projected to be operating in the region, including new and emerging players such as Bangladesh and Thailand. Despite major financial constraints, the Philippines is also seriously considering submarines as part of its long-term naval modernisation programme.
But the Asia-Pacific submarine scene is more than just a numbers game. New boats entering service are increasing in physical size, which translates into greater onboard spaces for combat systems, fuel and battery capacity, and better crew habitability. These result in the ability to remain out at sea for longer durations and farther away from home bases. These new submarines are also increasingly quieter, capable of prolonged submerged endurance, and equipped with a more comprehensive array of sensors and long-range strike weapons, including anti-ship and land attack cruise missiles.
Given that submarines are extraordinarily costly to acquire, operate and maintain, most Asia-Pacific navies would operate small undersea fleets. Seen in this light, larger submarines offer redundant room for extending service lifespan and incorporation of new technologies prior to their eventual replacement. For small and medium navies of the Asia-Pacific, regardless of their fleet sizes, the submarine arm constitutes a "strategic asset" that enhances peacetime deterrence and in times of conflict, at least poses a psychological hindrance to the adversary.
During the Falklands War in 1982, a single Argentine submarine tied down a significant portion of the UK Royal Navy in anti-submarine efforts, whereas a British submarine sank an Argentine cruiser, thus deterring Bueno Aires from further major naval action for the remainder of the campaign. Clearly, the operational value brought about by the submarine would continue to motivate regional governments to obtain even a small, token undersea combat force, which may come in handy given prevailing Asia-Pacific geopolitical uncertainties.
Yet this very geopolitical context creates room for concern. Amid simmering tensions in the East and South China Seas, Korean Peninsula and the Taiwan Strait, many of the contending rivals operate submarines - with new, more capable ones entering service within years. Moreover, the proliferation of submarines also motivates Asia-Pacific navies to acquire countervailing capabilities against the growing undersea threat.
Amid simmering tensions in the East and South China Seas, Korean Peninsula and the Taiwan Strait, many of the contending rivals operate submarines - with new, more capable ones entering service within years. Moreover, the proliferation of submarines also motivates Asia-Pacific navies to acquire countervailing capabilities against the growing undersea threat.
For example, China clearly recognises the potential challenge posed by its neighbours' submarine acquisitions. While its aircraft carrier and other major warship programmes have often seized much of the public attention, Beijing is also quietly yet steadily building its anti-submarine capabilities, such as corvettes specially optimised for such missions. In the same vein, the Indonesian and Philippine navies, for instance, also acquired anti-submarine helicopters targeted at the regional proliferation in the undersea domain.
In such a context, the employment of submarines for peacetime surveillance missions within foreign maritime zones and disputed waters, and the presence of countervailing, anti-submarine capabilities altogether heighten the risk of incidents, especially in times of tensions. Imagine a "Whiskey on the Rocks" incident in the disputed Asia-Pacific waters, reminiscent of the Soviet submarine U-137 which ran aground near a key Swedish naval base in 1981.
Even more ominously, the dense maritime traffic plying the Asia- Pacific littorals, as well as platforms - for example ultra-large crude carriers with draught as deep as 24m - fishing trawlers, submarine cable-laying ships and offshore energy rigs, all create potential navigational hazards that could increase the risk of underwater mishaps. Such eventualities, should they occur in times of interstate tension, may result in a diplomatic disaster and undermine mutual confidence and trust.
This is not to say that Asia-Pacific governments are not preparing for such eventualities. Some of them have acquired specialised rescue capabilities and trained together in various bilateral and multilateral settings, such as Exercise Pacific Reach, to respond to submarine emergencies. Yet these efforts are far from uniform throughout the region. Considering the diverse and often competing national interests in the Asia-Pacific, an institutionalised, region-wide form of submarine incident prevention and mitigation mechanism has a long way to go before it can be realised.
The very nature of the "Silent Service" tends to oblige navies not to divulge those submarines' exact locations - information which would be closely guarded by naval planners in peacetime so as to render tactical and operational advantages in times of conflict. However, it should not stop the establishment of small-scale national and sub-regional initiatives, such as the Submarine Safety Information Portal (SSIP) recently unveiled by the Republic of Singapore Navy, aimed at sharing information to prevent and mitigate underwater accidents.
Given the submarine proliferation that looks set to persist in the Asia-Pacific, it is never timelier for regional governments to evolve existing preventive and mitigation measures to forestall untoward incidents in the underwater domain. Initiatives such as SSIP and other existing measures could serve as building blocks for more developed, institutionalised regional mechanisms in the foreseeable future, such as an underwater version of the Code of Unplanned Encounters at Sea.
• The writer is a research fellow with the Maritime Security Programme at the S. Rajaratnam School of International Studies based in Nanyang Technological University.