Japan Has an Army — Here's How It's Different

Japan Forward

09-07-2025

Does Japan Have an Army? Ask around outside Japan, and you'll get a range of answers, from "No, they're pacifist" to "Sort of?" to "Isn't it just the United States protecting them?" The confusion is understandable. Japan is the world's third-largest economy and has one of the most advanced militaries, yet its Constitution renounces war and prohibits the maintenance of land, sea, and air forces.
The reality is more nuanced. Japan does have a military — a large, well-equipped one. But it operates under strict legal constraints and a different name: the Self-Defense Forces (自衛隊, Jieitai). Established in 1954 from a US-designed police reserve, the SDF is structured into Ground, Maritime, and Air branches. It exists only for self-defense, disaster response, and peacekeeping.
The legal basis for this posture is Article 9 of Japan's postwar Constitution. It "forever renounces war" and declares that Japan will "never maintain" armed forces. Successive governments have interpreted this to allow the minimum necessary for self-defense. For decades, this excluded offensive weapons and overseas combat.
That began to shift in 2014, when then-Prime Minister Shinzo Abe's administration interpreted the law to permit collective self-defense, supporting allies under attack. Their analysis deemed that this was possible without formally amending the Constitution.
Security laws passed later, in 2015–16, allow limited use of force abroad, but only under strict conditions. Namely, Japan must face an "existential threat," and any action must be proportionate and defensive in nature. Members of the Ground Self-Defense Force fire a 155mm howitzer FH70 during the Fuji General Firepower Exercise, August 25, 2019, at the Ground Self-Defense Force Higashifuji Training Range in Shizuoka Prefecture. (©Sankei by Yosuke Hayasaka)
Shaped by this "defense-only" mandate, the SDF is nevertheless a modern force. It fields advanced equipment, like F-35 fighter jets, Aegis destroyers, and PAC-3 missile systems. Also, it is acquiring long-range counterstrike capabilities. However, its mission is strictly defensive — to intercept missiles, secure sea lanes, support allied forces logistically, and respond to attacks on Japanese territory.
It cannot conduct independent combat operations abroad. International deployments remain limited to peacekeeping and disaster relief. In other words, even under the authority of collective defense, the SDF's use of force is tightly restricted. For example, its support of US forces cannot include frontline combat. Any deployment abroad must be justified under Japanese law, and offensive actions remain politically sensitive.
Rising threats from North Korea and China have spurred public support for changes. Japan is increasing its defense budget dramatically, with spending reaching ¥7.7 trillion JPY ($48.5 billion USD) in 2024, about 1.6% of GDP. It plans to hit 2% by 2027. The SDF is also gaining new capabilities: counterstrike missiles, integrated missile defense, cyber forces, and advanced surveillance systems.
Some argue this stretches the definition of purely defensive, especially as Japan looks to deter gray zone aggression, such as cyberattacks, air and maritime incursions, before they escalate. Nevertheless, the government firmly maintains that all new capabilities are consistent with its defensive posture and deterrence strategy.
While Japan maintains a quasi-alliance with Australia and various defense-related agreements with other countries, its only true alliance is with the United States. It hosts major US bases for the region, and the two work closely on missile defense and joint operations. In 2025, Japan joined a new trilateral defense dialogue with the US and Australia. Furthermore, it welcomed the creation of a Joint Operations Command with America's Indo-Pacific Command. Japan is also increasing cooperation with NATO and has taken part in joint cyber and intelligence exercises. In addition, it has contributed aid and equipment to Ukraine.
These moves also reflect growing concern over China's maritime aggression and North Korea's missile and nuclear programs. Japan cites these threats in its national security strategy to enable new spending and expanded roles for the SDF.
Japan's defense model is rare: a major economy with advanced military capabilities but no formal "army" and no conscription. Its 250,000 active personnel operate under civilian control and are limited to non-offensive roles abroad. In some ways, this resembles Germany's postwar military, but Japan's constitutional constraints are even tighter.
These are compounded by the country's postwar nuclear allergy, which has constrained serious debate about deterrence. Japan's adherence to the Three Non-Nuclear Principles has restricted its strategic options and limited the effectiveness of US-extended nuclear deterrence. As a result, Japan's current security posture may be inadequate in the face of growing nuclear threats from China, North Korea, and Russia. A JSDF member carefully transfers a mock shell into a blast-resistant container during an unexploded ordnance disposal drill. April 2024, Naha City (©Sankei by Naoki Otake).
Despite its strength, the SDF cannot legally call itself a military and remains tightly bound to a self-defense posture. That makes Japan an outlier among advanced nations, balancing modern security needs with lingering postwar pacifism.
This balance is under debate. The ruling Liberal Democratic Party has long supported revising Article 9 to explicitly acknowledge the SDF. In 2024, then-Prime Minister Fumio Kishida's party backed a proposal to clarify the SDF's legal status. A 2025 Asahi Shimbun poll found 53% of Japanese support constitutional revision.
So, Japan does have a military — powerful, professional, and evolving — but it remains legally unique. Driven by external threats and shifting public opinion, the Self-Defense Forces are growing in strength and responsibility. Yet their role is still bounded by law, politics, and history. Whether Japan's defensive creed can adapt to modern challenges without losing its identity is one of the country's defining security questions.
Author: Daniel Manning