Sage Wen and Hening Zhang
Vol. 40 Associate Editors
Article 51 of the U.N. Charter allows all member states to exercise the right to attack a third country if it assaults an allied nation. However, Japan is not currently able to fully exercise this right of collective self-defense because it cannot be reconciled with Article 9 of the Japanese Constitution. Article 9 stipulates that “the Japanese people forever renounce war as a sovereign right of the nation,” and that “land, sea, and air forces, as well as other war potential, will never be maintained.”
But Japan has had a de facto military since the 1950s known as the Self-Defense Forces (“SDF”). Is this legal? Further, should Japan, as a member state of the U.N., be able to exercise self-defense when being attacked, or even collective self-defense when its ally is under attack?
The answer to this question has produced a sharp split among Japanese constitutional scholars. When the Constitution went into effect in 1947, a majority of scholars agreed that it banned any war potential, even for self-defense. However, because of the US–Japan Mutual Defense Assistance Agreement, signed in 1954, Japan was obliged to strengthen its defense capabilities. When the SDF was set up in 1954, the government started arguing that self-defense is an inherent right for a sovereign state to “ensure its survival” and that possessing a “minimum armed organization” to uphold that right is not banned by Article 9.
The government found its constitutional justification in Article 13, which provides that “the people’s right to life, liberty and the pursuit of happiness shall be the supreme consideration.” Given this, the Constitution cannot be interpreted to prohibit Japan from using the minimum force required for self-defense when directly attacked and in the absence of other alternatives. However, this interpretation seems to be in direct conflict with Article 9’s prohibitions. The issue then becomes whether the SDF is considered as “other war potential.”
According to the Japanese government, the SDF does not constitute “war potential” prohibited by Article 9 because of existing constitutional limitations on Japan’s self-defense capacity. The limitations are: First, Japan is only permitted to possess the minimum necessary defense forces. This limit depends on the prevailing international situation, the standards of military technology, and various other conditions. However, whether the armed strength corresponds to “war potential” banned in Article 9 is an issue that relates to the total strength Japan possesses. Accordingly, whether the SDF are allowed to possess certain armaments depends on the judgment whether its total strength will exceed the minimum necessary limitation imposed by Article 9. For example, it is a common view that Japan is not permitted to own powerful weapons like intercontinental ballistic missiles, long-range strategic bombers, and attack aircraft carriers.
Second, Japan has also maintained an exclusively defense-oriented posture. Due to Article 9’s restrictions, the Japanese government has traditionally taken the position that it will only exercise self-defense when the following three prerequisite conditions are met: (1) there is an imminent and illegitimate act of aggression against Japan; (2) there is no appropriate means to deal with this aggression other than resort to the right of self-defense; and (3) the use of armed strength is confined to the minimum necessary level.
Third, before 2015, the Japanese government acknowledged that Japan was not allowed to engage in collective self-defense because defending another country would exceed “the minimum use of force” limitations under Article 9. But in 2015, Japanese Prime Minister Shinzō Abe managed to change the interpretation of Article 9 so that Japan can partially exercise the right of collective self-defense. Abe argued that given recent changes in Japan’s “security environment,” an alliance with other countries, especially the US, is now essential for Japan’s defense, for example, defending a U.S. military ship or aircraft involved in a joint operation to defend Japan.  He has argued that in a situation like this, if Japan does not try to defend U.S. military personnel risking their lives to defend Japan, it could critically damage the Japan-U.S. military alliance.
This argument suggests that Article 9 does not ban collective self-defense if “Japan’s survival” is at stake and “the people’s right to life, liberty and the pursuit of happiness is fundamentally overturned” due to an armed attack by a third country to Japan’s ally [the U.S.]. In other words, under the new interpretation, Japan is not allowed to engage in collective self-defense to defend an ally unless it is also required to defend the fundamental rights of the Japanese people. However, the “fundamental rights” of the Japanese people are an abstract concept, and it is unclear under which circumstances Japan would be allowed to engage in collective self-defense. Abe’s opponents have argued that the SDF’s military operations would need to be greatly expanded to aid the U.S. military. They contend that the new interpretation of Article 9 violates Article 9.
Now Abe and the ruling Liberal Democratic Party (“LDP”) are taking a step further and proposing to have Article 9 revised so that Japan can fully exercise the right of collective self-defense as defined under Article 51 of the U.N. Charter. But due to strong public preference for maintaining the status quo of the SDF, Abe’s current proposal only adds one paragraph to Article 9 which claims that the SDFs do not fall within the banned category of “war potential.” Abe has stated that the amendment would not change any of the legal restrictions already imposed on SDF operations. His position is that the strong skepticism about the government’s interpretation of Article 9 must be addressed by amending the Article and clarifying Japan’s military ability.
Despite Abe’s claims, many scholars still believe the SDF is technically unconstitutional given Article 9’s plain language. They argue that if the amendment would not change the substance of the SDF’s operations as Abe has claimed, then there is no need to have a national referendum over his proposed addition to the constitution. Some critics are afraid the revision would result in there being no restrictions on the SDF’s activities – as long as it’s called the SDF, it can be constitutional regardless of its scope of missions or weapons it might possess.
Though it remains questionable whether Abe will be able to push through the constitutional amendment in the near future, he has set 2020 as the deadline. This remilitarization attempt has triggered responses from nearby countries. China’s state news agency – Xinhua – criticizes Abe’s government as trying to jeopardize geopolitical stability in Asia-pacific again in a commentary. A right-leaning Korean newspaper, Munhwa Ilbo, expressed similar concerns in an editorial suggesting that the amendment may functionally reopen the path for Japan to wage war or engage in skirmishes with its neighbors.
Since the present Constitution of Japan was enacted in 1946, it has never been amended. Amending the constitution requires two-thirds support in both houses of the Diet, followed by a national referendum in which a bare majority would suffice. The LDP controls parliament with support from a smaller coalition ally, but it’s unclear if Abe’s coalition partners will back the proposal. LDP leaders acknowledge they don’t expect to win support from major opposition parties. Surveys show a Japanese public split on the issue. Polls taken by three national daily newspapers showed that at least half of respondents opposed the idea of Japan exercising its right to collective self-defense, with a third or fewer in favor. Therefore, while the practical goals of Abe’s ministry behind this constitutional move may remain a long way off, legitimizing SDF’s status is likely to have a substantial impact on the balance of geopolitical power in Asia-Pacific.
 U.N. Charter, art. 51. Under international law, it is understood that a state has the right of collective self-defense, the right to use force to stop armed attack on a foreign country with which it has close relations, even when the state itself is not under direct attack.
 The Constitution of Japan, art. 9.
 Byron Tau, Abe’s Window of Time for Amending Japan’s Pacifist Constitution Narrows, The Wall Street Journal (Aug. 12, 2018), https://www.wsj.com/articles/abes-window-of-time-for-amending-japans-pacifist-constitution-narrows-1534075201?ns=prod/accounts-wsj.
 Reiji Yoshida, Abe’s Route to Revising Article 9 Crosses Minefield of Legalese, The Japan Times (Mar. 12, 2018), https://www.japantimes.co.jp/news/2018/03/12/reference/abes-route-revising-article-9-crosses-minefield-legalese/#.W80dNxNKhE5.
 The Constitution of Japan, art. 13.
 Ito v. Minister of Agriculture, Forestry and Fisheries, 712 Hanrei jiho 24 (Sapporo S. Ct., 1973).
 Japan Defense Agency, Government View on Article 9 of Constitution, From Japan Defense Agency Web Site, http://www.jda.go.jp/e/policy/f_work/frame12_htm.
 Curtis J. Milhaupt, et al., The Japanese Legal System: Cases, Codes, and Commentary 229 (2012).
 Supra note 3.
 Supra note 9.
 Japan: Interpretations of Article 9 of the Constitution, The Law Library of Congress (September 2015), https://www.loc.gov/law/help/japan-constitution/interpretations-article9.php#_ftnref154.
 Kuni no sonritsu o mattou shi, kokumin o mamoru tameno kireme no nai anzen hosho hosei no seibi ni tsuite [Regarding Development of Seamless Security Legislation to Ensure Japan’s Survival and Protect Its People], National Security Committee & Cabinet Decision, July 1, 2014, http://www.cas.go.jp/jp/gaiyou/jimu/pdf/ anpohosei.pdf, English translation available on Cabinet Secretariat’s website, at http://www.cas.go.jp/jp/gaiyou/ jimu/pdf/anpohosei_eng.pdf.
 LDP Constitution Amendment Promotion Headquarters Chief, Mr. Hajime Funada, Gap from the Reality, Change it with Courage, Sankei Newspaper (May 4, 2015), http://www.sankei.com/politics/news/150504/ plt1505040001- n1.html.
 Supra note 3.
 https://www.nytimes.com/2016/07/12/world/asia/japan-election-shinzo-abe.html?_ga=2.260101321.519460364.1539633824-1108437695.1538141193; https://www3.nhk.or.jp/nhkworld/zh/news/105141/.
 The Constitution of Japan, art. 96.