After WW2 Japan capitulated and was disarmed. And as I know Japan was not able to have its own army, and its boundary would be protected by the United States. So, does Japan have the legal right to have its own army or navy? I was not able to find any worthy information in Google or Bing.

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    I'm tempted to give a complementary answer to the two we already have. However, it would entirely involve the modern political environment in that region. That leads me to think you might consider asking this same question over on Politics.SE.
    – T.E.D.
    Apr 5, 2013 at 23:22
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    "should" is a opinion/judgement and is way out of scope for H:SE. None of us can say whether a nation should have a military. Do they have a legal right? that is covered by their constitution as cited in the answers.
    – MCW
    Aug 10, 2015 at 13:08
  • Is the question asking about the Japanese Constitution, or the general international-law or treaty basis for having militaries?
    – smci
    Nov 7, 2016 at 6:52
  • This is not history, but current law. Of course all current law, for any country grew out of history, but I think there must be a better venue for this question.
    – user18963
    Apr 23, 2018 at 12:17

3 Answers 3


There are basically two answers to your question. The first comes from the legal precedents in the Japanese constitution, peace treaties, etc. The second is the de facto version of what actually happened after the war, and up to now.

Legally speaking, Japan was forbidden from having any kind of standing army, though they were permitted to have forces for their own self defense. Japan has never relied on the United States or any other country or governing body for its own protection in a strictly legal sense. In other words, the United States or United Nations never signed anything saying they would protect Japan.

However, in reality Japan does have a standing army in the form of its Self Defense Forces. Their military expenditures are in the top 10, and it is one of the most advanced armies in the world technologically, but still very small in terms of the number of people. The main difference after WWII is that Japan pledged never to deploy their forces abroad for any reason, though in the past 10-15 years they have been involved in some overseas peacekeeping, and contributed a destroyer and a refueling ship as a support asset to the war in Afghanistan. At this point, if Japan decided to increase the size of its military it wouldn't really be forbidden from doing so, but Japan has kept its military small by choice because, frankly, it's much cheaper.

Finally, while the United States never formally agreed to protect Japan the number of US military bases in the country means that, in a practical sense, it does. This has also allowed Japan to get away with keeping its military small, since the US Navy and other assets are spread all around Japan and S Korea. As far as the future goes, it's harder to say because the US has been rolling back military expenditures. It wouldn't be surprising to see the US encouraging Japan to increase the size of its military in order to decrease reliance on the US for protection, but it could easily go either way.

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    Article 9 of the Japanese Constitution is still in force. Japan is forbidden from keeping an army or resolving disputes through war. Apr 5, 2013 at 23:36
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    @Samuel Russell constitution is internal to Japan. But is there any treaty that forbids this?
    – Anixx
    Apr 6, 2013 at 2:09
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    @MarkC.Wallace In a legal sense you are absolutely right, the foundation of the treaty rests atop the constitution. In a practical sense a treaty can have more force than a constitution if there is a strong external motivator. Eg: Interwar Germany obeyed the limitations from the Treaty of Versailles (for a while) because of the credible threat of external punishment even though the government internally was in constant flux.
    – Odysseus
    Aug 11, 2015 at 17:08
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    @MarkC.Wallace Or you can look at it this way: there doesn't have to be an actor that enforces the constitution - indeed, in certain countries the constitution isn't worth the paper it's written on -, but some treaties, especially with a certain superpower, will almost certainly be enforced with its fleet of aircraft carriers if it's in the superpower's interests to do so. Sep 22, 2015 at 19:35
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    It also should be noted that the creation of the JSDF was actually MacArthur's own maneuvering around Article 9 by saying it was a police force, not a military force. the JSDF itself still receives plenty of opposition to its existence from its creation to now regardless of Abe's antics. Sep 22, 2015 at 19:37

Security Challanges: Japan’s Defence Dilemma is an interesting document. It sheds some light on this history of balancing constitution (and anti-militaristic sentiment associated), Japan's strategic objectives and its alliance with the United States. It takes the view that Japan has been subverting Article 9 to "normalise" the state. It also points out that a major problem with extending the role of the JSDF (or "Normalising" its role) would be to "normalise" the relationship with the US and perhaps risk losing the US's large protective presence. However it also questions how much Japan's refusal to take a normal military role may already be jeopardizing its relationship with the US. It's an interesting view and seems to echo what the other answers are saying.

Here's an extract:

Normalisation by Stealth

The entire course of Japan’s post-war defence policy has been a slow march towards normalcy. In practice, Japan’s so-called ‘peace constitution’ has only delayed but not prevented progress towards normal statehood. Initially, successive Japanese governments engaged in a process of ‘revision by reinterpretation’ as a way of circumventing constitutional prohibitions. More recently ‘revision by legislation’ has been the preferred method of change. Both the Iraq deployment and the dispatch of naval forces to the Indian Ocean in support of the coalition in Afghanistan have been authorised by specific items of legislation in 2001 and 2003. These capped a series of laws enacted over the past decade, which have expanded and diversified the roles and capabilities of Japan’s Self-Defence Forces (SDF). Successive Japanese governments have accumulated a series of faits accomplis, creating the necessary precedents for the acquisition of new functions by the SDF.

2 Article 9 of the Japanese Constitution – the so-called ‘Peace Clause’ – has been consistently interpreted by the Japanese government as prohibiting Japan’s exercise of its right to collective self-defence (meaning military action to defend the United States or its forces) as well as Japanese participation in collective security operations under UN auspices. However, Japan’s inherent right to collective self-defence as a sovereign state has never been abrogated, and indeed is recognised under the UN charter. The prevailing interpretation of Article 9 on collective self-defence was made in 1981 by the Cabinet Legislation Bureau. It stated: ‘It is recognized under international law that a state has the right of collective self-defense, which is the right to use actual force to stop an armed attack on a foreign country with which it has close relations, even when the state itself is not under direct attack. It is therefore self-evident that since it is a sovereign state, Japan has the right of collective self-defense under international law. The Japanese government nevertheless takes the view that the exercise of the right of self-defense as authorized under Article NINE of the Constitution is confined to the minimum necessary level for the defense of the country. The government believes that the exercise of the right of collective self-defense exceeds that limit and is not, therefore, permissible under the Constitution’. Quoted in R J Samuels, ‘Constitution al Revision in Japan: The Future of Article 9’, The Brookings Institution, Center for Northeast Asian Policy, 15 December 2004, www.brookings.edu/fp/cnaps/events/20041215.pdf.


Formally, Japan has no right: http://en.wikipedia.org/wiki/Article_9_of_the_Japanese_Constitution#Debate

Substantively, the Japanese state has taken such a right: http://en.wikipedia.org/wiki/Japan_Self-Defense_Forces#History

Politically, as the Chinese state has a great interest in Japan's capacity for aggressive war, Japan's interpretation of Article 9 both formally and substantively is closely watched by a large heavily armed state.

  • doesn't answer the question per se. Japan has a right to defend itself, like any other nation state. If they have (semi) voluntarily absolved themselves of the right to do so outside their national borders that doesn't mean they don't have a right to their armed forces.
    – jwenting
    Apr 18, 2013 at 6:48
  • Art.9: "Aspiring sincerely to an international peace based on justice and order, the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as means of settling international disputes. (2) To accomplish the aim of the preceding paragraph, land, sea, and air forces, as well as other war potential, will never be maintained. The right of belligerency of the state will not be recognized." Either sovereignty can self-limit, in which case I've provided an answer, or sovereignty can't self-limit, in which case by referring to the JSSDF: an answer. Apr 18, 2013 at 9:46

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