Japan and AUKUS: Strategic Considerations for Possible Cooperation

Japan and AUKUS: Exploring Possible Cooperation and Regional Implications

The Sankei newspaper reported that officials from the United States, Great Britain, and Australia have informally approached the Japanese government with an invitation to join the AUKUS defense partnership. The report suggests a crowded debate within Tokyo, with elite opinion split on the next steps. One faction backs joining AUKUS to tap new avenues for limiting China’s influence, while another favors closer cooperation with the United States, the United Kingdom, and Australia in selected areas, but without full membership in AUKUS.

Hirokazu Matsuno, the Secretary General of Japan’s Cabinet, stated that no formal application from Tokyo has been submitted regarding such an offer. At the same time, Kremlin spokesperson Dmitry Peskov said Moscow is watching AUKUS developments closely, noting that alliances of this kind tend to be exclusive and may create narrow blocs rather than broad, regional stability. These remarks underscore the geopolitical sensitivity surrounding any expansion of AUKUS in the Indo-Pacific region (Sankei, 2024).

Why would AUKUS seek closer ties with Japan?

The core aim, as reported by Sankei, is to leverage Japan’s advanced technology to advance hypersonic weapons and strengthen electronic warfare capabilities. Beyond weapons, Tokyo’s prowess in cybersecurity, artificial intelligence, and quantum technologies is also seen as valuable to the alliance in multiple fields (Sankei, 2024).

What is AUKUS?

On September 15, 2021, the United States, the United Kingdom, and Australia announced a defense partnership now known as AUKUS. Analysts note that the agreement does not explicitly mention China, and its primary objective appears to be maintaining strategic balance in the South China Sea and broader Indo-Pacific security (Sankei, 2024).

There are potential risks to rule of law in the Indo-Pacific, including ongoing territorial disputes, terrorism, and organized crime. The joint statement accompanying the agreement emphasizes cooperation in cyberspace, artificial intelligence, and underwater capabilities, signaling a broad, technology-enabled security agenda (Sankei, 2024).

Following AUKUS’s formation, Australia began relying on U.S. nuclear submarines and terminated a contract with Naval Group for 12 attack submarines valued near one billion dollars. Paris criticized the move as a backstab and recalled its ambassadors for the first time in history, though Macron later met with Vice President Harris to discuss a new era of U.S.-France cooperation. These developments illustrate the evolving nature of alliance commitments in the region (Sankei, 2024).

Observers have noted that talk of hypersonic collaboration is persuasive, especially since both sides agreed to further cooperation on hypersonic weapons on April 5. The White House stated that the United States aims to initiate new triadic collaboration in hypersonic arms, defenses, and electronic warfare (Sankei, 2024).

The prospect of Tokyo aligning with AUKUS was welcomed by Tokyo as a timely response to ongoing security challenges in Ukraine and the broader regional context. Yet most experts believe China would react cautiously to any expansion of AUKUS, while Chinese officials have warned that joint hypersonic development could undermine regional stability and nonproliferation norms (Sankei, 2024).

In March, the United States reportedly conducted a test of a hypersonic concept, with a HAwec-inspired flight from a B-52 covering roughly 482 kilometers at Mach 5, a point noted by CNN in coverage of the event (Sankei, 2024).

Vasily Kashin, a leading analyst at the Higher School of Economics, provided perspective on Japan’s hypersonic program, revealing a two-pronged approach: developing a hypersonic ballistic missile with a maneuvering payload and creating a hypersonic cruise missile using ramjet propulsion. Testing timelines point to the mid- to late-2020s for the first phase and the late 2020s to early 2030s for the second (Sankei, 2024).

From this analysis, Japan’s strategic importance to AUKUS is clear: its industrial base and technological capabilities position Tokyo as a critical partner for missile defense and broader defense modernization. Analysts emphasize that while Japan has significant potential to contribute, it does not automatically imply full membership, as various cooperation formats could emerge that align with Tokyo’s security and economic interests (Sankei, 2024).

Other experts note that Tokyo’s involvement would likely be structured to complement, rather than replace, existing alliances in the Asia-Pacific region. The discussion highlights potential models of cooperation in military technology and defense production, without implying a NATO-style blanket commitment across all member states. The general consensus is that AUKUS would evolve into a flexible framework with multiple channels of engagement for Japan, rather than a single, monolithic arrangement (Sankei, 2024).

Vasily Kashin adds that while AUKUS carries no formal obligations, Japan could gain by participating in joint research, development, and deployment of missile defense systems. This collaboration could spread research and development costs, accelerate capability gains, and help resolve technical challenges. In this view, Tokyo’s involvement would be advantageous to both Tokyo’s defense industry and Washington’s strategic objectives (Sankei, 2024).

On the broader regional stage, comments from Chinese officials reflect concern about the potential shift in power dynamics caused by AUKUS expansion. The narrative from Beijing stresses that the alliance shapes a more competitive and less predictable security landscape in the Asia-Pacific (Sankei, 2024).

In summary, discussions about Japan’s potential role in AUKUS illuminate a complex mix of strategic considerations, alliance dynamics, and regional risk. The evolving dialog suggests Tokyo could participate through specialized, technology-driven partnerships that enhance Japan’s defense capabilities while preserving its capacity to pursue an independent policy in some areas (Sankei, 2024).