Japan's Evolving Military Strategy: From Defense to Counterstrike

Japan is undergoing a transformative shift in its military strategy, moving beyond a strict defensive posture towards a more assertive counterstrike capability. This change is underscored by the recent successful tests of the Tomahawk missile and the Upgraded Type-12 missile, both designed to strengthen Japan's deterrence in the Indo-Pacific region.

In late July, Japan made headlines when the Japan Maritime Self-Defense Force, in collaboration with the US Navy, launched a Tomahawk land-attack cruise missile from the Kongo-class destroyer JS Chokai. This development positions Japan as the third nation to conduct such a launch from a surface vessel, demonstrating its expanding military capabilities.

Simultaneously, testing has commenced for the air-launched Upgraded Type-12 Surface-to-Ship Missile from the Japan Air Self-Defense Force’s F-2 fighter at Gifu Air Base. This missile, designed for low-observable, networked operations, could strike targets at ranges of 1,600 kilometers, significantly enhancing Japan's maritime-strike capabilities.

To support this shift, Tokyo is procuring 400 US-made Tomahawk missiles as a temporary measure while it develops its domestic missile systems with the aim to have them operational by fiscal year 2027. However, this strategy seeks to deter potential aggression from China without completely abandoning Japan's traditional defensive posture.

Despite these advancements, the expansion of Japan's missile capabilities appears to be outpacing the necessary infrastructure for effective deployment. A significant challenge lies in Japan's current dependency on US systems for comprehensive intelligence, surveillance, and reconnaissance (ISR). This reliance hinders Japan’s ability to independently launch credible counterstrikes.

A 2026 report by the International Crisis Group highlights that Japan still lacks a self-sufficient kill chain essential for identifying and tracking targets, launching strikes, and assessing damage. Such reliance means that Japan’s counterstrike capabilities could be compromised in the face of geopolitical tensions.

Experts, including Rupert Schulenburg from the International Institute for Strategic Studies, have noted that while the integration of Tomahawk missiles offers Japan a formidable naval deep-strike capability, there’s a pressing need for better synchronization with US operational strategies to ensure these assets can be reliably deployed when necessary.

Moreover, Kaitlyn Early and Carl Rehberg in their analysis argue that Japan's newfound capabilities could suffer from diplomatic rifts among allies and disruption from potential aggressors like China. They caution that Japanese missiles could lose credibility unless US systems for ISR, planning, and operational execution are effectively integrated.

Combat logistics also present a hurdle. Reports indicate that Japan’s defense industry lacks the scale and resilience necessary for sustained military operations. Critical munitions, especially Tomahawk missiles, are subject to long lead times, extending up to 47 months due to increased global demand and competition arising from ongoing conflicts.

Additionally, Japan's focus on high-cost military platforms, such as F-35 fighters and Aegis-equipped vessels, has come at the expense of a robust missile stockpile. This raises concerns about the nation's readiness for intense combat scenarios that require considerable missile inventories and auxiliary forces.

Another core issue is the need to navigate the legal and doctrinal parameters surrounding Japan's military capabilities. The evolving discourse within Japan is shifting from whether the country should have long-range missiles to the conditions under which they might be deployed. Legal scholars Charlotte Boring and Wrenn Yennie Lindgren emphasize that the government contends strikes on hostile territories can be justified if they adhere to self-defense principles.

However, ambiguity regarding the threshold for such actions complicates the narrative, creating room for interpretations that might lead to preemptive strikes, thus straying from Japan's longstanding defense-focused policy. The opposition parties continue to challenge the government by questioning the parameters triggering a counterstrike.

As Japan forges ahead with missile acquisitions, a pressing test remains: can it establish robust operational rules, stockpile sufficient munitions, and form alliances that can withstand the pressures of crisis without undermining its political strategy centered around defensive legitimacy? How Japan addresses these challenges will define its military posture and influence regional stability in the years to come.