Japan Sells Lethal Weapons Responding to US Demand, Using Ukraine as Excuse

Some media reported Japan’s recent policy change to sell weapons to the US as a break from its pacifist principle. However, Washington and Tokyo have been watering it down for a long time.

Co-development of Next-Generation Aircraft

On December 9, 2022, the leaders of the UK, Italy, and Japan issued a Joint Leader’s Statement regarding cooperation in the joint development of next-generation fighter aircraft, and the three countries signed on December 14, 2023.

Accordingly, on March 26, 2024, the Japanese government amended the Implementation Guidelines for the Three Principles on Transfer of Defense Equipment and Technology, avoiding discussion in the Diet. The amendment enables Japan to export the finished aircraft to other countries.

The arms exports are limited to the countries that concluded a promise with Japan to use the weapons Japan exports in a manner that meets the Charter of the United Nations’ purpose and principle. According to the Japanese Defense Ministry, as of March 26,  the countries that fulfill this term are the US, the UK, France, Germany, Italy, Sweden, Australia, India, Singapore, Philippines, Indonesia, Malaysia, Vietnam, Thailand, and UAE.

Tokyo stated that Japan needs the amendment because if Japan can not export the co-developed jets to other countries directly, it can not contribute to reducing the cost of development and production. To achieve a fighter jet that meets Japan’s necessary performance, Japan has to obtain the ability to negotiate in joint development.

Article 3 of Japan’s Three Principles requires that the countries to which Japan exports weapons and technology obtain prior consent from Japan before transferring weapons and technology to third parties. In December 2022, the Japanese government specified the procedure in the Guidelines to conduct co-developed weapons transfers to third parties smoothly.

On April 25, 2024, the Japanese Diet started discussing the idea of a treaty to establish an international organization responsible for aircraft co-development.

Three Principles on Arms Exports and Their Related Policy Guidelines

Before the Japanese government adopted the Three Principles on Transfer of Defense Equipment and Technology in 2014, Japan had long adopted the Three Principles on Arms Exports and Their Related Policy Guidelines. The old Three Principles, not legislation, embodied Japan’s pacifist policy.

On April 21, 1967, at Diet, Prime Minister Eisaku Sato explained the Ministry of International Trade and Industry’s (present Ministry of Economy, Trade and Industry) criterion that Japan didn’t permit the export of weapons to the three areas: communist countries, countries where the United Nations resolution banned weapon exports, and countries being at war or possibly being at war. This statement was the so-called Three Principles on Arms Export, not a new policy.

The word weapon was defined as military uses and for combat directly.

On February 27, 1976, Prime Minister Takeo Miki submitted the Governmental Unified Opinion on Arms Export, which Miki read at the Diet. This paper was not a new statement either, but it showed a policy formed by the Japanese government.

Since Sato explained at Diet, Tokyo had stated that weapons export to areas the Three Principles didn’t ban were permitted but showed a deliberate attitude. The Governmental Unified Opinion read the exports were refrained.

After that, the government explained that refraining meant Japan couldn’t export weapons as a rule. The Three Principles still showed Japan’s pacifist policy.


There are roughly two exceptions to the Three Principles: weapons exports to the US and particular cases. These exceptions watered down the Principles. The US has been clearly a party to conflicts, but the Japanese government regards the US as an exception.

In 1983, the Yasuhiro Nakasone administration enabled the provision of weapons technology to the US. In 2004, the Junichiro Koizumi administration decided to launch the joint development and production of a Ballistic Missile Defense System and permitted related exports to the US. In these cases, logically, even if Japan judges the US as a country at war, Japan can offer weapons and technologies.

On the other hand, since 1991, Tokyo has permitted the export of weapons in particular cases. Almost every time, the Japanese government stated that it maintained the basic idea of the Three Principles. These specific cases are taking out necessary weapons for the Japanese Self-Defense Forces’ overseas operations, mutual offers with allies or friendly countries, support to removing landmines, implementation of disposal of abolished chemical weapons, support for measures against terror and pirates, and supplying ammunition to the United Nations Peacekeeping Operations, etc.

In 2011, the Yoshihiko Noda administration further deregulated the Three Principals. Therefore, Japan can make a comprehensive exception concerning peace contribution, international cooperation, and joint development and production of weapons for Japan’s security.

In 2014, the Shinzo Abe administration abolished the Three Principles on Arms Exports and established the Three Principles on Transfer of Defense Equipment and Technology, which are still in force.

In the new Three Principles, The government “reexamined its past policy on the overseas transfer of defense equipment and technology, and, while giving due consideration to the roles played by the past policy,  comprehensively consolidated it to adapt to the new security environment, reflecting the past exemption measures made to date, and set out clear principles as Three Principles on Transfer of Defense Equipment and Technology,” and declared to carry forward with the transfer of defense equipment and technology in the joint public and private efforts.

Japan Helps Destroying Ukraine

On March 8, 2022, the Japanese government decided to provide Ukraine with non-lethal supplies to support the invaded country, such as bulletproof jackets, helmets, clothes for cold weather, cameras, tents, sanitary goods, emergency foods, and generators. However, the Three Principles didn’t specify whether Japan could transfer bulletproof jackets to Ukraine, so Tokyo revised the Implementation Guidelines the same day. Also, Japan provided Ukraine with 101 Self-Defense Force vehicles from May 2023 to March 2024.

The old Three Principles didn’t strictly specify the countries at war or possibly at war. The new Three Principles defines parties to the dispute as countries where the UN Security Council takes measures to sustain or recover international peace and security after a military attack occurs. So, the rule doesn’t apply to Ukraine. Under this criterion, Japan can transfer weapons even to Israel.

On December 22, 2023, the Japanese government amended the new Three Principles and its Guidelines. The amendment enables Tokyo to export finished lethal weapons manufactured by Japan to the patent country. On the same day, Japan decided to export the Patriot missile to the US because the US demanded Japan make up the US stock shortage caused by the Russia-Ukraine war. This export was the first finished lethal weapon transfer since Tokyo established the new Three Principles, and Japan helped the US prolong the devastating war.

Japan’s Public Opinion

Japan can’t refuse the US’s request. For instance, in 2014, there was a symbolic happening.

On July 17, 2014, the Japanese government officially decided to export the seeker gyro part of the Patriot PAC-2. The Japanese defense company Mitsubishi Heavy Industries manufactured the parts for the Japanese Self-Defense Force, receiving a license from Raytheon. Though the US planned PAC-2 exports to other countries, Raytheon had already ended the gyros production. So, the US demanded Japan supply the part. However, before Tokyo decided, the US signed an agreement with Qatar on July 14 to sell weapons, including the Patriots. The Japanese government’s discussion and decision were only a formality.

The US seems to have influenced the next-generation jet project. Washington and Tokyo agreed to co-develop autonomous systems capabilities to support the aircraft’s combat. Thus, the US backs to profit from the joint development of the UK, Italy, and Japan.

Japan’s public has long opposed weapons exports. Though the Japan Business Federation has requested that the government strengthen the defense industry and weapons transfer, and even if the US demands it, Tokyo cannot change its principles or guidelines rapidly. Japanese defense companies, which also make civilian goods, are reluctant to be merchants of death. Since Tokyo adopted the new Three Principles in 2014, Japan has exported only air defense radars to the Philippines as finished weapons.

Some Japanese media and experts are using the Russian invasion of Ukraine and China’s threats to promote weapons exports and appeal to public opinion.

According to a poll that the Kyodo News conducted in May 2023, 20% of Japanese people said that Japan should lift the ban on exporting lethal weapons, 54% said that Japan should limit its weapons exports to non-lethal weapons, and 23% said that Japan should ban weapons exports completely. 77% of Japanese opposed lethal weapons exports.

Also, according to a poll on exporting joint-developed defense equipment to other countries that the Japan Broadcasting Corporation conducted in March 2024, only 4% of Japanese people said Japan should permit it, 54% said Japan should limit the countries, and 32% said Japan should not permit it.

However, considering what has happened until now, Japan will probably move forward with weapons transfers slowly, repeating government changes.

Reiho Takeuchi is a Japanese journalist whose work focuses on international politics. He has written a series of articles titled US Military and Modern Colonialism on substack.