Podcast Episode Summary

Podcast: New Books Network
Host: Nicholas Gordon
Guest: Stephen C. Mercado
Book: Japanese Spy Gear and Special Weapons: How Noborito's Scientists and Technicians Served in the Second World War and the Cold War
Release Date: October 30, 2025

Overview

In this episode, host Nicholas Gordon interviews Stephen C. Mercado about his new book exploring the secretive and innovative work of the Noborito Research Institute—Japan’s clandestine military research center before and during World War II, and into the early Cold War. Mercado discusses the history, science, ethics, and legacy of the institute, whose scientists and technicians developed everything from balloon bombs and counterfeited currency to “death rays” and biological weapons.

Key Discussion Points & Insights

Origins and Purpose of the Noborito Research Institute

• Noborito was part of a broader network: One of ten Imperial Japanese Army Technical Research Institutes, Noborito (the 9th) was unique in its focus on covert warfare and intelligence support, unlike its sibling institutes which focused on conventional arms.

  • “Noborito was in charge of unconventional or special research.” — Stephen Mercado [03:52]

• Motivation for the book: Mercado was inspired by Noborito’s recurring mention during his earlier work on Japan’s Nakano School and finally took up the challenge of a dedicated history two decades later.

  • "I felt that it was such an interesting topic in its own right that I would do a book just on the Boruto one day. And it took me about 20 years to get back to the idea, but I finally did..." — Mercado [02:57]

Major Projects and Technologies

• “Death Ray” Development

  • Japanese scientists were influenced by global fascination with electromagnetic weaponry, encouraged by names like Marconi and Tesla.
  • The hope was a technological breakthrough—possibly a weapon that could interfere with engines or kill personnel—would offset Japan's growing disadvantages as the war turned against them.
  • “There was the idea that powerful waves… could interfere with an engine's operation or even stop the engine from running. […] If it succeeded, it could give Japan an advantage because there was no way that Japan could, through conventional means, stave off defeat by the Allies.” — Mercado [06:10 | 07:54]

• Counterfeit Currency

  • The goal: undermine resistance in China by flooding the economy with fake currency, inspiring hyperinflation and economic chaos.
  • “They thought let's destroy the economic basis for resistance... by counterfeiting Chinese money.” — Mercado [12:50]

• Balloon Bombs

  • Ingenious paper balloons, designed to ride the transpacific jet stream and drop incendiary and explosive bombs on America, marked the first bombs dropped on the contiguous United States.
  • Originally, they were considered as a weapon against the Soviet Union, but strategic desperation turned their focus to the US.
  • “So using… Japanese paper and a paste made from mulberry bark […] they succeeded in creating a balloon that could survive the passage across the Pacific.” — Mercado [15:43]
  • The psychological impact was prioritized over accuracy or destruction.
  • There were secret plans to use these balloons for biological warfare—specifically, to disperse cattle plague and possibly other pathogens.
  • “The original intent was to put some of these [biological] weapons on the balloons… They had actually succeeded in developing cattle plague as a weapon.” — Mercado [17:25]

• Biological and Chemical Warfare

  • Noborito was a hub for clandestine bioweapon and poison development, focusing more on assassination and covert operations than mass battlefield use.
  • The institute aimed to create delayed-action poisons for subtle assassinations.
  • “They were developing a delayed effect poison so that you could assassinate someone... and then the victim wouldn't die, like say for 10 hours or the next day.” — Mercado [20:08]
  • Noborito complemented notorious units like 731, providing technical expertise in support of Japan’s broader biological warfare ambitions.
  • “Japanese army had decided that they would go with biological. […] the Japanese had developed a premier BW [biological warfare] effort in the world.” — Mercado [19:33]

Researching the Institute

• Historical Sources and Difficulties
  • Most official records were destroyed at Japan's surrender per direct orders—Noborito was prioritized even above the notorious Unit 731 for document destruction.
  • Mercado relied on memoirs, interviews with surviving staff, history museums, and veterans’ testimonies.
  • “They set about destroying basically everything official related to special research. […] I had to rely on memoirs… there’s a history museum at the site of the old Noborito... that publishes reports.” — Mercado [21:43–22:54]

Personal Reflections of Former Personnel

• Moral Responses and Guilt
  • Mixed feelings among former staff—some rationalized their work as wartime duty, others chose not to attend reunions due to feelings of guilt, especially those in biological warfare.
  • “Some of the veterans would not attend those meetings. And apparently this was often the case for those involved in biological warfare… That… would make them feel guilty.” — Mercado [25:58]

Postwar Fate and Allied Interest

• Immediate Aftermath
  • The institute and its military intelligence functions were abolished; buildings became part of Meiji University.
• US Exploitation of Expertise
  • Americans interrogated staff, seeking to harvest technical knowledge as they had from German scientists postwar.
  • Notably, neither Unit 731 nor Noborito staff saw prosecution; instead, some were recruited by the US military—notably the counterfeiters, who aided clandestine operations during the Korean War.
  • “Nobody from unit 731 and nobody from Noborito went up for the Tokyo War Crimes Tribunal. Nobody was tried from either group. […] The US Government recruited a number of the counterfeiters... and this work continued into the second half of the 60s.” — Mercado [28:30, 30:16]

Legacy and Memory

• Public Recognition in Japan
  • While unknown in the West, Noborito’s history is reasonably acknowledged in Japan, thanks in part to research and exhibits at the university’s on-site museum.
  • “It's fairly well known in Japan. […] it's acknowledged that some of the things that were done there, you know, were in contravention of international law and morality.” — Mercado [33:51]

Notable Quotes & Memorable Moments

• On the Death Ray:
  "Even Nikola Tesla, who's famous now because there are a lot of cars with his name on it. Tesla in 1934 said that he had developed a death ray... But he said the drawback was that it would require such a massive power supply that he could only envision putting it on something very large, like a battleship." — Mercado [06:43]

• On Counterfeiting as Strategy:
  "The way we can do that is by counterfeiting Chinese money. Then we'll insert it into the economy and there'll be so many Chinese banknotes floating through the economy that inflation will become worse and worse." — Mercado [12:53]

• On Clandestine Science:
  "Noboruto was probably more involved in doing the, we could say, clandestine efforts. So a lot of it would be more like. Some of it was assassination. That was what the poisons were for." — Mercado [19:57]

• On the Destruction of Evidence:
  "He sent out a directive on August 15 alerting everyone involved to destroy everything involved with special research. And Noborito was number one on the list. Noborito was above unit 731." — Mercado [22:02]

• On Postwar Reuse:
  “Some of these people [counterfeiters] recruited by the US Government […] were creating these documents, and this work continued into the second half of the 60s.” — Mercado [30:14]

Key Timestamps

• Institute overview and origins: [02:50–05:05]
• Death ray project: [05:05–08:24]
• Counterfeit currency operations: [11:46–14:05]
• Balloon bomb development and biological plans: [14:05–18:54]
• Biological/chemical weapon research: [18:54–21:16]
• Challenges of historical research: [21:16–24:17]
• Personal feelings of former staff: [24:17–27:06]
• Postwar dissolution and Allied interest: [27:06–33:00]
• Legacy, memory, and museum: [33:00–34:28]
• Where to find the book and future projects: [34:51–36:00]

Closing

Mercado’s Japanese Spy Gear and Special Weapons uncovers the shadowy, inventive world of wartime Japanese clandestine science, exploring not only the technological marvels and moral nightmares of Noborito, but also the postwar fates, legacies, and uncomfortable complicity of scientists and foreign powers alike.