[Japan’s Voices No.5] Japan’s Challenges in Bolstering Its National Security in a Disorderly World

Review of Japan’s National Security Strategy under the Takaichi cabinet

The government of Japan under Prime Minister Sanae Takaichi has pledged to revise the 2022 National Security Strategy by the end of 2026. Following the ruling coalition’s supermajority victory in the recent Lower House election, the Cabinet is expected to shape a new strategy that squarely addresses the increasingly acute and complex security environment surrounding Japan.

Geographically, Japan is situated in one of the most strategically sensitive regions in the world, neighboring three authoritarian states. Political decision-making in such states is often opaque and difficult to predict or restrain. Russia’s aggression against Ukraine shows no sign of ending. China has become more assertive in the East and South China Seas and is intensifying pressure on Taiwan. Russia and China continue to deepen their alignment under their “no-limits” partnership. Meanwhile, North Korea’s denuclearization appears ever more unlikely. Pyongyang is supporting Russia’s war effort while gaining political, economic, technological and military benefits from Moscow. These circumstances have made Japan fully aware of the gravity of its strategic environment.

The rules-based international order in crisis

The maintenance of the rules-based international order grounded in the rule of law is in Japan’s national interest, as it provides predictability and contributes to global stability and prosperity. However, this order faces serious challenges. Not only are Russia and China contesting it from the outside, but the United States is also disrupting it from within.

In his memorandum on the subject of the 2026 National Defense Strategy, the U.S. Secretary of War Pete Hegseth describes the rules-based international order as “a cloud-castle abstraction.” One senior official publicly asserted that we live in a world that is governed by force. Soon after that, the U.S. President himself said that his own mind is the only thing that can stop him and that he does not need international law. Uttering these words could carry significant implications, particularly when accompanied by policies that reflect such views.

The Trump administration defines U.S. national interests narrowly, without prioritizing  fundamental values and long-standing principles. It has also questioned the significance of alliances and partnerships, weakening U.S. soft power and, over time, its hard power. For Japan, whose national security and diplomacy rest heavily on the Japan-U.S. Alliance, this situation creates a strategic dilemma.

Security challenges for Japan

The rules-based international order rests not only on norms but also on power. Yet power without legal and normative foundations is naked violence, degenerating into coercion. Japan would not wish to live in a Hobbesian world of “struggle of all against all” and where might makes right. Therefore, reinforcing and restoring the rules-based order is an urgent priority for Japan.

To contribute meaningfully, possibly even to lead, international efforts to uphold this order, Japan must first strengthen its own power and prepare for worst-case scenarios. Today’s security challenges are multifaceted, encompassing nuclear intimidation, conventional military threats, gray-zone and hybrid contingencies, and economic coercion. Military operational domains have expanded to include land, sea, air, outer space, cyberspace, and the cognitive domain.

Located in a volatile strategic setting, Japan has no choice but to enhance its comprehensive national power, including diplomatic capacity, defense capabilities, economic resilience, technological innovation, intelligence capabilities, and human resources.

While Japan’s defense capabilities are already substantial, they are not sufficient in an era of protracted and total warfare as demonstrated by the war in Ukraine. A sustained dramatic increase in defense expenditure is therefore necessary – not to satisfy the ally, but to build a more versatile, agile, sustainable and operationally ready force for Japan’s own defense.

The Japan-U.S. Alliance will remain indispensable. However, redefinition of the alliance  will be necessary, as Japan will need to assume greater roles in response to a more severe security environment. Ensuring the credibility of U.S. extended nuclear deterrence remains a critical issue, given that Japan’s own nuclearization is not strategically viable.

At the same time, it would be premature to move away from the United States. Rather, diversifying and strengthening partnerships with other like-minded countries will be essential, both to uphold the international order even in the absence of the United States and to encourage continued U.S. engagement. The vision of a Free and Open Indo-Pacific will remain the basic vision to promote Japan’s international partnerships. How to “strategically advance and evolve” this vision in ways that enhance the autonomy and resilience of partner countries will be a key question.

The next National Security Strategy will need to address all these issues and more. This strategy document will be a long to-do list, but strategy is fundamentally about prioritization. Given limited resources, not everything can be treated as equally urgent. Determining what to prioritize – and how to sequence policy responses – will be a crucial test of Japan’s political leadership.

The views expressed in this article are the author's and do not reflect those of JIIA CGO.