The signals are getting clear enough: Japan is becoming an ally of Australia. The latest indication is that Japanese Defense Minister Shinjiro Koizumi is this week visiting Australia for the second time in four months.
Standing next to her Australian counterpart, Anthony Albanese, in May, Prime Minister Sanae Takaichi described Australia as a ‘quasi-ally’ – joining analysts who had concluded that the relationship had got that far. The time has come for Australian politicians to refer to Japan as an ally, even if they feel the need for qualifiers such as quasi or de facto. The term ‘ally’ makes sense even though the two countries still lack a treaty committing them to mutual defence.
Australia is as invested in Japan as Japan is in Australia. Canberra may not yet have gone as far as Takaichi’s description of the relationship – but Defence Minister Richard Marles has gone pretty close. Speaking alongside Koizumi in Tokyo in April, he said, ‘there is no country in the world with whom we have a greater strategic alignment than Japan’. Japan is now Australia’s most important defence partner behind the United States, and, we would argue, ahead of Britain.
If a benchmark for alliances is regular consultation, Australia and Japan are hitting the KPIs. But willingness to act is also necessary, and that is where the relationship has gathered speed. One reason for so much ministerial travel is Australia’s decision to buy up to 11 frigates of Japan’s Upgraded Mogami class, developed from the Mogami class that’s already in Japanese service. The defence ministers signed the deal for the first three frigates during Koizumi’s previous visit, in April.
Unfortunately, the unexpected change of New Zealand’s defence minister last week probably spoiled the opportunity for a trilateral meeting to discuss Wellington’s potential acquisition of Upgraded Mogamis. The first trilateral between the defence ministers of these countries happened at the Shangri-La Dialogue in Singapore in May, so a meeting in Canberra this week could have kept up momentum.
The potential for the Upgraded Mogamis to become the next-generation ANZAC frigate is an example of how Australia will benefit, economically and strategically, as Japan expands its security assistance and transfers defence equipment to more countries across the region. Perth, where most of Australia’s Upgraded Mogamis are to be built, could become an operational and sustainment hub for several countries operating Japanese weaponry. These may soon include the Philippines and Indonesia if they receive older warships from Japan. Similarly, several operators of Japanese kit could train with it in Australia’s spacious and secluded testing grounds.
These geographic advantages help explain why Albanese and Takaichi issued a joint statement in May saying that ‘Japan and Australia are increasingly vital to each other’s strategic depth’. Australia’s greater distance from China and its strike missiles makes it an attractive place for Japan to set up defence industries and stockpile supplies. Australia is a vital source of critical minerals and energy, and the southern route around Australia could connect Japan to the Indian Ocean if conflict closed the Strait of Malacca and other routes through the Indonesian archipelago.
From Canberra’s perspective, Japan has the capital, technological know-how and industrial heft to help Australia revive manufacturing and make its economy more resilient to coercion and other supply shocks. A military reciprocal access agreement with Japan helps the Australian Defence Force utilise Japanese facilities in fulfilling missions along the First Island Chain in the Western Pacific, including sanctions enforcement against North Korea. Australia’s presence in multilateral operations around this area reinforces freedom of navigation and deterrence.
One important aspect of bilateral strategic depth is the convergence of strategic viewpoints between Canberra and Tokyo. Both recognise that China is the main threat to regional stability. The Takaichi administration has been more willing to say so out loud, though recent public responses by the Australian government, including to China’s testing of a submarine-launched nuclear-capable ballistic missile, suggest Canberra is again recognising the value of speaking up – for deterrence and public awareness.
Importantly, both countries acknowledge that US hard power is indispensable, and that the best way to keep any US administration engaged in the Indo-Pacific is by showing Washington that its allies are willing to carry a fair share of the security burden.
This strategic alignment will allow Marles and Koizumi to cut to the chase in their private discussions this week. They can compare notes about what to do if Iran sustains its stranglehold on the Strait of Hormuz, for example, and how to shape American thinking ahead of the expected upcoming meeting of presidents Donald Trump and Xi Jinping. They will also discuss how to further develop strategic ties with India, where Koizumi will head after Australia. With US-India relations under strain, it’s incumbent on Australia and Japan to keep the Quad moving in the right direction.
Koizumi’s visit is an opportunity to brief Marles about updates to Japan’s National Defense Strategy and its Defence Buildup program. Both ministers committed to such consultations when they established a new framework for strategic defence coordination last December, and Marles flew to Tokyo just before the publication of Australia’s 2026 National Defence Strategy.
Given the level of strategic alignment and cooperation with Japan, Australian ministers should begin referring to Japan as an ally. There’s currently no collective defence treaty between the two countries, and Japan is unready to sign one. But that could change as the regional outlook worsens and Japanese public opinion towards China keeps hardening. Australia’s recent signing of collective defence treaties with Papua New Guinea and Fiji shows they can be negotiated rapidly. It’s always better to do so before a crisis, though.
Fear of China’s response is not a good reason for failing to call Japan an ally. Such angst is self-fulfilling because it encourages further pressure from Beijing. So, let’s hope that when both defence ministers exchange compliments in front of the cameras this week, they call each other allies, quasi or otherwise.