Speculation is again growing that Japan may plan to acquire nuclear powered submarines.
Japanese media interest in this issue peaked in late September last year, immediately after Australia made a surprise announcement that it would acquire this technology as part of its AUKUS deal with the United States and the United Kingdom.
That announcement was made just prior to Japan’s ruling Liberal Democrat Party’s (LDP) leadership election. Two candidates for this position, former Minister of Defence Taro Kono, and the current head of the LDP’s Policy Research Council Sanae Takaichi, voiced strong support for following Australia’s lead.
However, both candidates were defeated by Japan’s current prime minister Fumio Kishida – who has publicly questioned whether nuclear submarines are necessary. On December 19, Japan’s new Minister of Defence, Kishi Nobou, followed up announcing that “there are no plans to discuss the acquisition of nuclear submarines in the near future".
Despite these developments, the party room remains divided on the issue. At the core of this division is competing visions about the types of roles Japan’s navy will play in the future. This issue is expected to be addressed via the late 2022 release of three key defence policy papers: the National Security Strategy, National Defense Program Guidelines, and the Medium Term Defense Programs. In a concession to foreign policy hardliners, Kishida has already stated that these reports will “consider all options without excluding them”.
Kishida, whose position on foreign affairs and defence has been described as “dovish”, has shown lukewarm interest in revising Japan’s pacifist constitution. In line with this, his position on nuclear submarines arguably stems from the view that Japan’s submarine force will primarily serve a coastal defence role, for which it is currently well suited.
However, this view was tied to his confidence that his administration could improve regional security by mending ties with China – which is already teetering. With Kishida showing growing support for the agenda of maintaining a Free and Open Indo-Pacific (FOIP), and with the United States pushing for Japan to play a more active role in making this happen, his administration may be forced to consider a wider role for the Japanese Navy.
For a conventional national or coastal defence role, Japan’s current submarine fleet, which currently numbers 22 undersea platforms, is one of the world’s best. Its new Taigei class (29SS) submarine, which is replacing Japan’s still-competitive Soryu class, is said to be equipped with pump-jets, which perform better in shallow water, and which have a smaller acoustic signature than conventional propellers. Its stealth capabilities – as well as its submergence times – have also benefited from Japan’s pioneering work on lithium-ion batteries and snorkelling technologies.
But in terms of the capabilities suited for long range expeditions, Japan’s fleet still lags nuclear submarines on the key metrics of speed, range, payload, and submergence times, the latter of which greatly impacts operational discretion. These deficiencies could become apparent if, as speculated by Jane’s Defence Weekly’s Kosuke Takahashi, Japan’s navy, at the behest of America, comes to play a regular part in exercises and operations in the South China Sea or beyond.
The pivotal questions is thus whether America – whose submarine fleet will shrink over the next few years – will push harder for Japan to play a more active role in supplementing or augmenting its own forces through regular participation in activities in the South China Sea or elsewhere.
On this front, momentum has been building. Gary Roughead, America’s retired Chief of Naval Operations, recently proposed that the US should “change the nature of our alliance with Japan”, whom he identified as “very proficient operators”. On the specific matter of undersea platforms, Ronald O’Rourke, an esteemed analyst for the Congressional Research Service, has identified an expansion of the “Japanese attack submarine force” as the “number one opportunity” to help overcome looming US shortfalls.
Significantly, these assessments have occurred in the backdrop of the rapid advancement of the Quad alliance, in which Kashida is playing an important role. American aspirations that its allies will “step up to the plate” in the Pacific, and thereby set back inchoate shifts in the balance of power in the region, were pressed home by US Secretary of State Antony Blinken after last Friday’s Quad meeting in Melbourne. Subsequent to the meeting, Japan’s Minister for Foreign Affairs Yoshimasa Hayashi – mirroring the assessment of Taro Kono – called Australia’s planned acquisition of nuclear submarines “important”.
It is possible that Hayashi’s statement, which has coincided with a recent uptick in Japanese media attention on the AUKUS deal, is testing the waters of public opinion. Some indication of whether this reflects a shift in Japan’s own position on the possession of nuclear powered submarines might be forthcoming in this year’s next Quad meeting, which is set to be held in Japan.