From the Kempeitai to a “spy’s paradise.” The history of Japanese intelligence since World War II.
Sanae Takaichi’s government has fulfilled one of the most important provisions of the coalition agreement: strengthening Japan’s intelligence services. Until now, Japan’s intelligence capabilities had been limited by decentralization and legal loopholes, which turned the country into a “spy’s paradise.” This state of affairs had persisted since the end of World War II, when, with the start of the American occupation, existing intelligence agencies—known for their brutality, such as the Kempeitai—were dissolved. In postwar Japan, there was a prevailing belief that intelligence agencies must be restricted to ensure civil liberties, and that U.S. intelligence operating in Japan until the end of the occupation would focus on combating foreign spy networks. As early as 1983, Japanese Prime Minister Yasuhiro Nakasone attempted to introduce a law on the protection of state secrets; however, strong public resistance and fears of a return to authoritarian practices pushed the issue to the sidelines for decades to come.
What did the previous model look like?
Japan’s existing intelligence apparatus was based on an extremely decentralized structure designed to prevent the emergence of a single, powerful operational institution. As a result, the state’s intelligence architecture resembled a mosaic of overlapping jurisdictions among several separate ministries, none of which, however, had the authority to conduct traditional foreign intelligence using covert means (HUMINT).
It is worth briefly explaining here the differences between the main intelligence disciplines used to collect and analyze information:
- HUMINT (Human Intelligence) – Human intelligence: Gathering information directly from people. This includes undercover operations, interrogations of prisoners and witnesses, interviews with defectors, as well as contacts with diplomats or informants.
- OSINT (Open Source Intelligence) – Open-source intelligence: The collection and analysis of data derived exclusively from publicly available, open sources. These include, among others, websites, social media, the press, commercial satellite imagery, court records, and databases.
- SIGINT (Signals Intelligence): The interception and analysis of electromagnetic emissions and communications signals.
- MASINT (Measurement and Signature Intelligence): The collection and analysis of physical data describing the characteristic features (known as “signatures”) of objects, phenomena, or weapons.
Japan’s intelligence structure to date has been divided into four main agencies:
- Cabinet Intelligence and Research Office (CIRO / Naichō): reporting directly to the head of government. Formally, it served as the chief analyst, but in practice it had a small staff and relied heavily on open-source intelligence (OSINT) and reports provided by other ministries.
- Public Security Agency (PSIA / Kōanchō): An agency under the Ministry of Justice, established in 1952. Although it was responsible for monitoring extremist political groups, subversive organizations, and espionage networks, the PSIA did not possess police powers—its officers could not make arrests or conduct wiretaps without the consent of external agencies.
- Public Security Bureau of the National Police Agency (NPA): Operates within the police structure and has real investigative and surveillance capabilities throughout the country. It focused on counterintelligence and counterterrorism, but its activities were strictly reactive and limited to Japan’s borders.
- Defense Intelligence Command (DIH / Jōhōbonbu): Established in 1997, this agency reports to the Ministry of Defense and is the largest intelligence organization in terms of personnel. Jōhōbonbu specializes in electronic intelligence (SIGINT), satellite reconnaissance, and military data analysis.
In addition to the lack of a traditional foreign intelligence agency, such as the U.S. CIA or the British MI6, the biggest problem with the Japanese model was the so-called “ministerial silos.” Individual agencies jealously guarded their sources, rarely sharing findings with their competitors. As a result, the prime minister and the government often received conflicting or delayed information. This tradition of rivalry among intelligence services in Japan dates back to the early 20th century, when tense relations between the Imperial Japanese Army (IJA) and the Imperial Japanese Navy (IJN) in their struggle for influence over the state led, in a sense, to the Russo-Japanese War (1904), the invasion of Manchuria (1931), the Second Sino-Japanese War (1937), and the attack on Pearl Harbor (1941). Furthermore, until the enactment of the State Secrets Protection Act in 2013 under Prime Minister Shinzō Abe’s administration, Japan lacked strict criminal penalties for disclosing classified state information to foreign entities. The lack of a coherent anti-espionage law and a uniform security clearance procedure meant that for decades, Tokyo was a relatively easy target for infiltration operations and economic espionage.
What does the new reform change? What is the structure of the new agency, and why was it needed?
The reform announced by Sanae Takaichi’s government aims to eliminate the weaknesses of the existing system by creating a consolidated, professional foreign intelligence agency—structurally modeled on British (MI6) and American (CIA) models, but adapted to the specificities of Japanese law, which means it will function primarily as a coordinator of various smaller agencies. The National Intelligence Bureau (NIB / Kokka Jōhō-kyoku) takes the place of the former CIRO, but with much broader powers.

The new agency is becoming the primary body responsible for conducting foreign HUMINT operations. Its establishment also resolves the issue of departmental fragmentation—the new agency assumes a leading role, taking precedence over the existing intelligence offices within ministries, and has easy access to information from other ministries and the ability to coordinate activities. The new agency has also been granted broad authority to protect key industrial sectors—including the semiconductor, artificial intelligence, and biotechnology industries, as well as critical infrastructure. Thanks to this drastic change—by the standards of Japanese politics—the Land of the Rising Sun can count on increasing internal security, which is particularly essential at a time when Japan is abandoning its pacifism and embarking on remilitarization in the face of a potential confrontation with China.
Bibliography
1. Statement by the Secretariat of Japanese Prime Minister Sanae Takaichi on the establishment of the National Intelligence Bureau (2026). https://www.cas.go.jp/jp/gaiyou/jimu/nic_nib.html
2. Yomiuri Shimbun. (2026). Japan Set to Launch National Intel Bureau on July 31. https://japannews.yomiuri.co.jp/politics/defense-security/20260724-339687/
3. Yeung, J. & Asada, Y. (2026). Japan is launching its first centralized intelligence agency since WWII. Here’s why.
4. Shido, H. (2021). Sharing Experiences in the 20th Century. NIDS Joint Research Series No. 19.