Jeffrey LewisDeath Cult Drones, Maybe

Did you know that, in the 1990s, the Aum Shinrikyo death-cult acquired two remote-controlled helicopters and considered using them to deliver chemical weapons? It’s a wild story, write Brian Scheu and Philipp Bleek — although one that raises more questions, including about sourcing, than it answers.

A terrible tale of drones, chemical weapons, and (gasp!) citation echo chambers

By Brian Scheu and Philipp C. Bleek

Gather round the campfire, because we’ve got a spooky story to share. It’s got malfeasance of the traditionally spooky kind, including terrible violence all the way up to mass murder. But it’s also got methodological malfeasance, specifically shoddy sourcing that we suspect is less of an anomaly than one might hope. Boo!

Drones in the hands of terrorists have been getting a lot of attention lately, including for the delivery of conventional explosives but also possibly chemical, biological, or radiological substances in future, though not everyone is equally spooked by the former and especially the latter. It seems that when the Japanese alternative medicine shop and yoga studio turned apocalyptic millenarian cult Aum Shinrikyo acquired two pricey remote-controlled helicopters and explored their use for delivering chemical weapons, that was the first documented case of terrorists considering drones to conduct attacks.

Aum is particularly notorious for a 1995 attack on the Tokyo subway with sarin that killed either 13 or 14 people; 13 died by the end of 1996, while a final victim was bedridden with severe brain damage and finally died March 10, 2020, almost 25 years after the attack. (As an aside, this is a thorny legal issue, and a longstanding common law practice holds that homicide charges are appropriate only if a victim dies within “a year and a day” of an attack.) Of course, the attack also injured, and terrorized, far more. Aum had robust chemical and biological weapons programs, though the latter was sufficiently bungled that no one was actually harmed by it, plus much less robust—in some cases farcically so—programs to develop nuclear weapons, space-based lasers, earthquake generators, and both procure and manufacture its own conventional weapons.

Aum made some striking acquisitions, including surplus Soviet-era military hardware from Russia. One acquisition, in either 1993 or 1994, was those two remote-controlled helicopters, sophisticated models with reported flight times of 90 minutes, capable of speeds up to 85 mph, and payloads of 18 pounds, both purchased for the equivalent of $36,000 from a commercial vendor (everything in this sentence and this and the following paragraph is sourced from Kaplan and Marshall’s book). Apparently the vendor who sold them was sufficiently concerned that he alerted the police—who failed to follow up, as they so often did in response to the cult’s often egregiously suspicious and lawbreaking behavior—though not sufficiently concerned to forgo $36,000 of spondulix.

The story of the remote-controlled helicopters ends happily; inept cult members apparently smashed one into a tree and the second into the ground, and that was the end of that. Whether and how seriously Aum considered using the helicopters to spread chemical or biological agents remains unclear. Many sources allege it, but the supporting evidence is limited to some cursory content in the Kaplan and Marshall book, including that the cult told the vendor they hoped to modify the helicopters—whose intended purpose was photography—for crop-dusting. And for readers hoping to hear more about blimp terrorism, sadly Kaplan and Marshall only mention the uncrewed blimp in passing and other sources don’t mention it at all. 

When we started looking into this, we thought it was robustly sourced, because dozens of sources are cited on it. But it turns out there’s only one solid source—Kaplan and Marshall’s book—plus two more that mention but shed no additional light on the purported drones. Those two additional sources include expert Kyle Olson’s testimony to a US government interagency symposium and a staff statement from a US Senate Permanent Subcommittee on Investigations report. Of the other sources, only about a third cite one or more of these solid sources, while about two thirds cite another source that itself doesn’t cite a solid source, creating an echo chamber of sourcing that looks robust at first glance but that provides no additional support for the claims. And even the writing that cites one or more of the solid sources also cites additional sources that add nothing, giving a mistaken impression of more robust support than actually exists. In addition to echo chamber, a colleague suggested this dynamic might be called illusory corroboration, corroboration exaggeration, corroboration misperception, or, more catchily, zombie sourcing (this isn’t really relevant, but we want to nod in the direction of Dan Drezner’s work on zombies and international relations theory).

We have a hunch that such citation echo chambers are more common than is widely appreciated. After all, it took us a lot of work to dig up various sources, and we only slowly realized that the impressive number of sources wasn’t so impressive at all.

In closing, we have some questions.

Substantively, what should we make of the Aum Shinrikyo case? In its interest in drones and various other technologies, and its considerable investment in chemical, biological, and to a far lesser extent even nuclear weapons, how much of an outlier was Aum Shinrikyo, and how heartened should we be by its failure to do more damage? Or to put it more succinctly, how spooked should we be by Aum? Reasonable people reasonably offer different answers to that question.

Methodologically, what about citation echo chambers, how common might they be? We suspect rather common, it’s easy to stumble into them via either accident or laziness, and the latter is probably the wrong word, because it takes considerable effort to avoid them. Not everyone can fact check to New Yorker standards.

It’s a spooky world out there, both in terms of violent actors and methodological miscreants. Try not to have nightmares about either tonight.

Brian Scheu is a graduate research assistant and Philipp C. Bleek is an Associate Professor of Nonproliferation and Terrorism Studies at the Middlebury Institute of International Studies at Monterey.