Tokyo Report | Security | East Asia

Breaking the Postwar Taboo: Japan Lifts Its Ban on Lethal Arms Exports

To fully understand its significance, we must situate the Cabinet decision within both its historical context and the evolving international environment.

A Type 88 surface-to-ship missile is test-launched by Japan’s 1st Artillery Brigade from Point Mugu Sea Range, California, the U.S., in July 2021.

On April 21, the Cabinet of Prime Minister Takaichi Sanae approved the removal of Japan’s longstanding ban on lethal weapons exports. The move drew sharp criticism from China, while receiving support from countries such as the United States and Australia. Regardless of one’s position, the decision is poised to reignite debate over whether Japan will continue its postwar pacifist trajectory, as well as accelerate discussions about the restructuring of the Indo-Pacific security architecture.

A policy shift of this magnitude – effectively overturning nearly 80 years of arms export restrictions – demands careful examination. To understand its significance, we must situate the change within both its historical context and the evolving international environment.

From Total Ban to Gradual Relaxation

In 1967, the Sato Eisaku Cabinet established the “Three Principles on Arms Exports,” which prohibited exports to communist bloc countries, states under United Nations’ arms embargoes, and countries involved in or likely to be involved in international conflicts. Coming at the height of the Cold War, this policy carried both moral and strategic weight: as a defeated power in World War II, Japan sought to regain international trust through institutionalized self-restraint.

In 1976, the Miki Takeo Cabinet further tightened these principles, expanding the ban to cover nearly all arms exports, with only minimal exceptions for technology transfers to the United States. For decades thereafter, Japan’s defense industry operated within a highly restrictive framework, serving almost exclusively the Self-Defense Forces while remaining largely absent from the global arms market.

The turning point came in 2014 under Prime Minister Abe Shinzo, who marked a broader shift from the Yoshida Doctrine toward a more proactive security posture (or Abe Doctrine). The Abe government replaced the old framework with the “Three Principles on Defense Equipment Transfers,” shifting the emphasis from prohibition to regulation and opening limited pathways for exports. In practice, however, exports remained confined to five non-lethal categories – rescue, transport, vigilance, surveillance, and minesweeping – while lethal weapons were excluded due to their incompatibility with Japan’s exclusively defensive and pacifist principles.

In 2023, the Kishida Fumio Cabinet further revised these rules, allowing Japan to export finished weapons produced under foreign licenses back to the licensing countries. Limited exceptions were also introduced for states facing unlawful aggression, most notably to facilitate ammunition support for Ukraine under the United States’ coordination. While framed as a technical adjustment, this shift marked a psychological breakthrough: it eroded the long-standing political consensus that Japan-made lethal weapons must not be exported.

In February 2026, Japan’s ruling Liberal Democratic Party moved to abolish the five-category restriction on non-lethal equipment, reclassifying defense exports broadly into “weapons” and “non-weapons” and expanding the scope of both arms exports and jointly developed systems. In this context, the Takaichi Cabinet’s formal approval of the change in April was simply the culmination of an ongoing trajectory.

What Is Japan Trying to Do?

Some analysts interpret this policy shift primarily as an effort to revitalize Japan’s domestic defense industry. This is indeed one factor considered by the government and Ministry of Defense. According to data from the Stockholm International Peace Research Institute (SIPRI), Japan’s major defense firms saw a 40 percent year-on-year increase in arms sales revenue in 2024, with the top five companies – including Mitsubishi Heavy Industries – reaching a combined $13.3 billion. Long dependent on a single domestic buyer, Japan’s defense sector increasingly requires economies of scale to sustain research and development.

More fundamentally, however, the shift reflects Japan’s reassessment of its role within the regional security architecture. Over the past decade, the Indo-Pacific has undergone a profound structural transformation driven not by a single event, but by the combined effects of the United States’ strategic retrenchment, China’s rise, and conflicts in other regions. In this context, Japan faces growing pressure to assume greater autonomy and share more security responsibilities in maintaining a free and open Indo-Pacific based on the rule.

This requires not only strengthening its own defense capabilities, but also building flexible security networks with like-minded partners through mechanisms such as minilateralism and lattice alliances.

The Philippines offers a particularly clear illustration. As tensions in the South China Sea intensify, the Marcos administration has sought deeper defense cooperation to balance pressure from China. Japan, in turn, views support for the Philippines’ defense capabilities as a strategic investment in stabilizing the First Island Chain. Initiatives such as Official Security Assistance (OSA), enhanced military-to-military cooperation, and defense equipment agreements form a mutually reinforcing network. For Manila, Japan provides an additional strategic pillar beyond the United States; for Tokyo, a more capable Philippines helps distribute risks across a wider maritime space.

Australia, at the same time, represents a different dimension of this strategy. Japan just signed a contract to export its Mogami-class frigates to Australia, underpinned by a “quasi-alliance” relationship that has already taken shape. The Australia-Japan Reciprocal Access Agreement (RAA), for example, enables the two countries’ forces to operate and train on each other’s territory. In this framework, defense exports are not merely commercial transactions, but instruments for deepening interoperability, aligning standards, and fostering a shared strategic language.

Taken together, these developments outline a broader evolution in Japan’s security strategy: a shift from the traditional U.S.-centered hub-and-spokes system toward a multilayered, lattice alliance structure. Emerging quadrilateral cooperation among the United States, Japan, Australia, and the Philippines reflects this trend. The Global Combat Air Program (GCAP) – a sixth-generation fighter being jointly developed by Italy, Japan, and the United Kingdom – represents its most ambitious manifestation. Under the new guidelines, jointly developed systems such as GCAP aircraft may be exported to third countries – marking the first time Japan has embedded its arms export potential within a multilateral defense industrial framework.

It is important to note that Japan’s policy shift does not eliminate institutional constraints. In principle, each arms export still requires approval from the National Security Council, and the government will monitor end-use. Exports of lethal weapons to countries actively engaged in war remain formally prohibited. Furthermore, current export destinations are limited to 17 partner countries with existing agreements, and any expansion of this list must undergo a rigorous political process.

However, the Takaichi Cabinet has chosen not to delegate these procedures to the Diet, retaining flexibility through the qualifier “in principle.” This creates room for maneuver: under certain circumstances, Japan could approve the export of jointly developed weapons to countries involved in armed conflict. Should such provisions be invoked during a specific crisis, their political implications would extend far beyond the legal text.

Domestic tensions are also significant. Opposition parties and segments of civil society warn that these incremental changes risk eroding the substantive meaning of Article 9 of the Constitution. Even as defense industry revenues rise, reluctance among researchers to engage in military-related projects remains a bottleneck, highlighting persistent divisions within Japanese society over its security identity.

For nearly eight decades, Japan’s self-imposed ban on lethal weapons exports has served as a cornerstone of its postwar pacifist image. The Takaichi Cabinet frames the current shift as necessary to ensure Japan’s security and contribute to regional and global stability. Critics, however, see it as a step toward dismantling the postwar order. Both sides draw on the same historical legacy – yet differ sharply on what obligations that legacy entails. This debate is unlikely to end with a Cabinet decision.

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On April 21, the Cabinet of Prime Minister Takaichi Sanae approved the removal of Japan’s longstanding ban on lethal weapons exports. The move drew sharp criticism from China, while receiving support from countries such as the United States and Australia. Regardless of one’s position, the decision is poised to reignite debate over whether Japan will continue its postwar pacifist trajectory, as well as accelerate discussions about the restructuring of the Indo-Pacific security architecture.

A policy shift of this magnitude – effectively overturning nearly 80 years of arms export restrictions – demands careful examination. To understand its significance, we must situate the change within both its historical context and the evolving international environment.

From Total Ban to Gradual Relaxation

In 1967, the Sato Eisaku Cabinet established the “Three Principles on Arms Exports,” which prohibited exports to communist bloc countries, states under United Nations’ arms embargoes, and countries involved in or likely to be involved in international conflicts. Coming at the height of the Cold War, this policy carried both moral and strategic weight: as a defeated power in World War II, Japan sought to regain international trust through institutionalized self-restraint.

In 1976, the Miki Takeo Cabinet further tightened these principles, expanding the ban to cover nearly all arms exports, with only minimal exceptions for technology transfers to the United States. For decades thereafter, Japan’s defense industry operated within a highly restrictive framework, serving almost exclusively the Self-Defense Forces while remaining largely absent from the global arms market.

The turning point came in 2014 under Prime Minister Abe Shinzo, who marked a broader shift from the Yoshida Doctrine toward a more proactive security posture (or Abe Doctrine). The Abe government replaced the old framework with the “Three Principles on Defense Equipment Transfers,” shifting the emphasis from prohibition to regulation and opening limited pathways for exports. In practice, however, exports remained confined to five non-lethal categories – rescue, transport, vigilance, surveillance, and minesweeping – while lethal weapons were excluded due to their incompatibility with Japan’s exclusively defensive and pacifist principles.

In 2023, the Kishida Fumio Cabinet further revised these rules, allowing Japan to export finished weapons produced under foreign licenses back to the licensing countries. Limited exceptions were also introduced for states facing unlawful aggression, most notably to facilitate ammunition support for Ukraine under the United States’ coordination. While framed as a technical adjustment, this shift marked a psychological breakthrough: it eroded the long-standing political consensus that Japan-made lethal weapons must not be exported.

In February 2026, Japan’s ruling Liberal Democratic Party moved to abolish the five-category restriction on non-lethal equipment, reclassifying defense exports broadly into “weapons” and “non-weapons” and expanding the scope of both arms exports and jointly developed systems. In this context, the Takaichi Cabinet’s formal approval of the change in April was simply the culmination of an ongoing trajectory.

What Is Japan Trying to Do?

Some analysts interpret this policy shift primarily as an effort to revitalize Japan’s domestic defense industry. This is indeed one factor considered by the government and Ministry of Defense. According to data from the Stockholm International Peace Research Institute (SIPRI), Japan’s major defense firms saw a 40 percent year-on-year increase in arms sales revenue in 2024, with the top five companies – including Mitsubishi Heavy Industries – reaching a combined $13.3 billion. Long dependent on a single domestic buyer, Japan’s defense sector increasingly requires economies of scale to sustain research and development.

More fundamentally, however, the shift reflects Japan’s reassessment of its role within the regional security architecture. Over the past decade, the Indo-Pacific has undergone a profound structural transformation driven not by a single event, but by the combined effects of the United States’ strategic retrenchment, China’s rise, and conflicts in other regions. In this context, Japan faces growing pressure to assume greater autonomy and share more security responsibilities in maintaining a free and open Indo-Pacific based on the rule.

This requires not only strengthening its own defense capabilities, but also building flexible security networks with like-minded partners through mechanisms such as minilateralism and lattice alliances.

The Philippines offers a particularly clear illustration. As tensions in the South China Sea intensify, the Marcos administration has sought deeper defense cooperation to balance pressure from China. Japan, in turn, views support for the Philippines’ defense capabilities as a strategic investment in stabilizing the First Island Chain. Initiatives such as Official Security Assistance (OSA), enhanced military-to-military cooperation, and defense equipment agreements form a mutually reinforcing network. For Manila, Japan provides an additional strategic pillar beyond the United States; for Tokyo, a more capable Philippines helps distribute risks across a wider maritime space.

Australia, at the same time, represents a different dimension of this strategy. Japan just signed a contract to export its Mogami-class frigates to Australia, underpinned by a “quasi-alliance” relationship that has already taken shape. The Australia-Japan Reciprocal Access Agreement (RAA), for example, enables the two countries’ forces to operate and train on each other’s territory. In this framework, defense exports are not merely commercial transactions, but instruments for deepening interoperability, aligning standards, and fostering a shared strategic language.

Taken together, these developments outline a broader evolution in Japan’s security strategy: a shift from the traditional U.S.-centered hub-and-spokes system toward a multilayered, lattice alliance structure. Emerging quadrilateral cooperation among the United States, Japan, Australia, and the Philippines reflects this trend. The Global Combat Air Program (GCAP) – a sixth-generation fighter being jointly developed by Italy, Japan, and the United Kingdom – represents its most ambitious manifestation. Under the new guidelines, jointly developed systems such as GCAP aircraft may be exported to third countries – marking the first time Japan has embedded its arms export potential within a multilateral defense industrial framework.

It is important to note that Japan’s policy shift does not eliminate institutional constraints. In principle, each arms export still requires approval from the National Security Council, and the government will monitor end-use. Exports of lethal weapons to countries actively engaged in war remain formally prohibited. Furthermore, current export destinations are limited to 17 partner countries with existing agreements, and any expansion of this list must undergo a rigorous political process.

However, the Takaichi Cabinet has chosen not to delegate these procedures to the Diet, retaining flexibility through the qualifier “in principle.” This creates room for maneuver: under certain circumstances, Japan could approve the export of jointly developed weapons to countries involved in armed conflict. Should such provisions be invoked during a specific crisis, their political implications would extend far beyond the legal text.

Domestic tensions are also significant. Opposition parties and segments of civil society warn that these incremental changes risk eroding the substantive meaning of Article 9 of the Constitution. Even as defense industry revenues rise, reluctance among researchers to engage in military-related projects remains a bottleneck, highlighting persistent divisions within Japanese society over its security identity.

For nearly eight decades, Japan’s self-imposed ban on lethal weapons exports has served as a cornerstone of its postwar pacifist image. The Takaichi Cabinet frames the current shift as necessary to ensure Japan’s security and contribute to regional and global stability. Critics, however, see it as a step toward dismantling the postwar order. Both sides draw on the same historical legacy – yet differ sharply on what obligations that legacy entails. This debate is unlikely to end with a Cabinet decision.

Haonan Hua is a researcher at the Graduate School of Media and Governance, Keio University. His research interests include East Asian international relations, Japanese politics and diplomacy.

Australia-Japan defense relations

Japan defense industry

Japan security diplomacy

Japan-Philippine defense cooperation

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