Defence cooperation between Australia and Japan has yet to find its top gear but, after a cautious start, that relationship is in pole position among Australia’s regional security partnerships. The road ahead may soon lead into new and productive areas of cooperation though this is also likely to test comfort levels and appetite for risk to a sharper degree than before.

Bilateral interaction between the two countries’ armed forces has visibly picked up over the past year. The deployment of several Japan Air Self Defense Force F-35A joint strike fighters to RAAF Base Tindal, last August, was a prominent milestone, officially inaugurating the reciprocal access agreement ^[1] (RAA), almost a decade after both countries agreed to negotiate one. A reciprocal deployment of RAAF F-35As to Japan, for Exercise Bushido Guardian ^[2], followed in September. In December, 230 Australian Army personnel took part in a command post exercise, Yama Sakura, for the first time, with US troops and Japan self defense ground Forces. And in February, ADF personnel deployed to Japan and Hawaii for Exercise Keen Edge 24 ^[3].

It is still relatively uncommon for the JSDF to conduct drills with non-US forces in Japan so ADF involvement in these exercises reflects Tokyo’s growing comfort with Australia as a defence partner.

Despite this intensification of activity, some frustration remains on the Australian side that the RAA is performing short of expectations. But the RAA does not regulate all military activity, and some continues to occur on an ad hoc basis. For decades, Australia has already had access to seven military bases in Japan, under a status of forces agreement tied to UN Command Forces Rear ^[4], headed by a RAAF officer, based at Yokota Air Base. This remains in play alongside the bilateral RAA for Australian defence activities specifically relating to Korean Peninsula security.

Perhaps the most telling feature of the bilateral defence relationship in this growth phase is that Japan now frequently takes the initiative in defence cooperation. This has included a willingness to discuss sensitive Taiwan scenarios that has sometimes challenged Australian comfort levels. The establishment of a genuine reciprocity among close partners tied to a common ally, in the US is a positive trend.

Cooperation could soon expand into wider areas of defence, testing integration between their wider industrial eco-systems. First, in the independent review ^[5] into Australia’s surface naval capability, Japan’s Mogami 30FFM multi-mission frigate ^[6], built by Mitsubishi Heavy Industries, was identified as a potential off-the-shelf fit for the replacement to the ANZAC-class. If Japan joins the fray by bidding to supply Australia with 11 future general-purpose frigates, the first three of which are to be built overseas and the remainder at Henderson in Western Australia, this could add extra ballast to the bilateral partnership in the form of a large-scale defence industrial collaboration.

Second, in a move that few observers foresaw, Japan could be officially invited by the AUKUS partners to participate in Pillar 2 as soon as April ^[7]. Either of these possibilities would bring a new dimension to the strategic partnership between Canberra and Tokyo. Both also come with significant risks attached, requiring close political handling, clear communication and mutual expectation management.

There is a strong feeling of déjà vu about the future frigate decision, recalling the outcome of the ill-fated SEA1000 decision, in April 2016. This saw Japan crashing unceremoniously out of Australia’s future submarine competition in circumstances that were unnecessarily humiliating. Prime Minister Tony Abbott had initially encouraged Tokyo to bid on broader strategic grounds, only for the government of his successor, Malcolm Turnbull, to opt for a French design over the Japanese (and German) offerings, on capability grounds. An important lesson from this diplomatic debacle was Australia’s error in sending mixed signals about the criteria for selecting the future submarine. The bilateral defence partnership eventually bounced back, but it was a jarring introduction for Japan to the Australian acquisition process.

Tokyo is likely to be wary about exposing itself to another potential bruising loss of face. The Mogami design probably has a better technical prospect ^[8] of success than some of its potential competitors, from Germany, South Korea and Spain, but Japan’s defence industry still falls behind on export experience and market savvy. Even a successful bid would be likely to strain relations, given Canberra’s expectations for delivering capability on a tight timescale and workforce strains in Western Australia. Those in charge of the frigate acquisition process should keep this context front of mind, and make deliberate efforts to be transparent and consistent with Tokyo in regard to the requirements and selection criteria. Appeals to the ‘strategic’ logic of choosing a Japanese design are otherwise likely to fall on deaf ears in Tokyo.

The parallel prospect of Japan’s participation in AUKUS Pillar 2, as a ‘plus’ partner, is not a bilateral defence issue per se, but could also change the dynamics of the defence relationship. During Deputy Prime Minister Richard Marles’s latest trip to Japan he made encouraging noises about the potential for partnering with Japan on Pillar 2 technologies. But a closer reading ^[9] of his comments suggests that Canberra remains cautious, alive to the risks of diluting the AUKUS partnership before it has begun to deliver submarine capability under Pillar I.

It now appears that Washington is intent on bringing Japan into Pillar 2 sooner rather than later, over any Australian and British qualms. An announcement about Japan’s inclusion could be made when Prime Minister Kishida visits Washington next month. There could be different motivations for this move, including the Biden administration’s cautionary desire to tightly bind its intra-alliance initiatives ahead of a possible change of US government. And Japan’s boost to defence spending under Kishida and its advanced technological base could invigorate AUKUS Pillar 2. However, Japan’s inclusion would also be bound to complicate AUKUS in process terms, while its ability to safeguard sensitive information still falls far short of the Five Eyes ^[10] intelligence sharing arrangement’s standards, though it is improving ^[11].

Canberra’s overriding priority remains the delivery of submarine capability under AUKUS Pillar 1. But given that Washington now appears determined to press ahead on Japan’s Pillar 2 invitation, Australia should probably just accept this as a fait accompli and try to shape the terms of Japan’s partnership, rather than wasting energy opposing it. Notably, in January, Australia’s Department of Defence publicly announced a research agreement with Japan to enhance strategic capabilities in robotic and autonomous systems for undersea warfare. The overlap with an AUKUS Pillar 2 designated workstream, one that also directly complements Pillar 1, seems to hint at a pragmatic Australian hedge towards Japan’s eventual inclusion.