The Abe administration is likely to treat Japanese makers’ participation as parts producers in the manufacture of Lockheed Martin F-35 Lightning II stealth jet fighter as an exception to Japan’s three-point ban on weapons exports.

Among the countries planning to procure the F-35 is Israel, which is caught up in international tension that could lead to military conflict. It’s possible that Japan could become involved in an international military conflict, albeit indirectly.

The Abe administration’s expected decision carries the danger of gutting the weapons exports ban. It should rethink its decision in view of the basic spirit behind the ban.

In 1967, Prime Minister Eisaku Sato set down the weapons exports ban by declaring in the Diet that Japan would prohibit weapons exports to communist countries, countries subjected to arms embargo under U.N. resolutions and countries involved or feared to be involved in international conflicts. In 1976, Prime Minister Takeo Miki strengthened the ban by banning the export of weapons to all countries. The ban follows the war-renouncing principle of Article 9 of the Constitution.

But later Japan made exceptions to the ban and provided parts to the United States under the Japan-U.S. Acquisition and Cross-Serving Agreement and engated in the joint development and production of a missile-defense system with the U.S.

In December 2011, the DPJ government led by Prime Minister Yoshihiko Noda decided to permit the joint development and production of defense equipment with other countries if the projects contribute to Japan’s defense. At the same time, it upheld the principle of not encouraging international conflicts.

Japan plans to eventually procure 42 F-35s, starting with the purchase of four aircraft in fiscal 2016. The United States, Britain, Italy and six other countries are jointly developing the F-35. Japan seeks an arrangement with the U.S. under which Japanese makers will produce parts, including wing parts, with a view to strengthening the foundation of Japan’s defense industry.

Although it is reported that the U.S. is ready to provide a list of countries to which the F-35s will be delivered, it is not certain whether Japan can block the delivery of the jet fighters to countries involved or feared to be involved in international conflicts. The simple fact is that the U.S. is often involved in war.

The practice of making one exception after another to the weapons exports ban will eventually render it ineffectual. Japan should halt this practice and make the ban effective again. At the very least, the government must make public what parts Japanese makers are going to produce for the F-35 to encourage meaningful discussions on the matter.

The F-35s that Japan’s Self-Defense Force has ordered are unlikely to be equipped with software needed to launch short-range air-to-air missiles. The F-35’s turning performance is also reported to be unsatisfactory. Given this, their purchase at more than ¥10 billion apiece might be a waste of public funds.