Japan, NATO, and the Diversification of Security Partnerships

Bringing in experts from Europe and Japan, this report examines the key shifts in the allies’ threat perceptions and strategic thinking on policy responses. It also explores the rise of informal security alignments designed to address both traditional and hybrid challenges and exemplified by the minilateral-type security cooperation pursued by Japan. Finally, the report zooms in on the growing interlinkages between security in the Indo-Pacific and Euro-Atlantic regions, as evidenced by the deepened security ties between like-minded partners.

The report argues that the Russian invasion of Ukraine should be seen as a critical juncture for alliance politics. Military alliances are now increasingly being operationalised to enhance military readiness and effectively generate combat power in case of a contingency. The US-Japan alliance, the report finds, should be perceived as a manifestation of some of the broad and enduring changes in the role of alliance politics in international security, which are observable both in the Western Pacific and Europe.

While the US-led alliance remains a key pillar of the security and defence policies of the ‘junior’ allies, notably Japan, the report highlights the allies’ uncertainties about the sustainability of the American security commitments, both in the Indo-Pacific and Euro-Atlantic region. Assessing Japan’s updated conceptualisation of security in the context of the Ukraine war and the rise of hybrid threats, the report detects a sense of urgency in Tokyo to develop a diverse set of capabilities and expand security partnerships. Australia, India, and the Republic of Korea remain a priority in terms of alignment cooperation.

At the same time, the changing nature of security challenges is steadily raising the importance of cooperation with geographically distant partners, as seen in Tokyo’s evolving security partnership with the EU and NATO. Japan’s strategic partnership diplomacy exemplifies a broader trend of strategic diversification. Tokyo has been successful in utilising alignment policy to promote an interconnected network and accomplish issue-based, functional cooperation in various areas.

From NATO’s perspective, addressing hybrid challenges requires collaboration with various actors, including geographically distant players. Minilateral and multilateral formats involving a small group of like-minded countries can provide NATO with the opportunity to work closely with Japan and other Indo-Pacific partners on specific issues, such as cyberattacks and disinformation campaigns.

The report thereby makes the following recommendations:

• The US and Japan should engage in robust bilateral discussions that examine possible future scenarios in the Western Pacific, clarify the allies’ division of labour, and address the trade-offs in defence planning both for effective deterrence and contingency planning.
• Japan, in cooperation with the US, should reinforce and institutionalise its ties with Australia, the ROK, and the Philippines in minilateral settings. Priority should be given to interoperability and joint deterrence that contribute both to Japan’s immediate security needs and address hybrid threats, especially in maritime security.
• Japan should pursue a tailored approach to its relationship with the EU by prioritising cooperation in the digital domains, new technologies, defence industry, and technology sharing.
• NATO and Japan should seek to establish communication channels and mechanisms to facilitate a coordinated response. Joint exercises and training should be prioritised. NATO, the EU, and Japan should explore ways to deepen trilateral security cooperation in tackling hybrid threats.

Japan should be involved in NATO’s and the EU’s Centres of Excellences, possibly as part of a minilateral grouping with other like-minded Indo-Pacific partners.

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