Was this an unusual number of cases in a large army with less than state-of-the-art medical services in an area where all these infections were long endemic? All those diseases also presented threats to armies during World War II and in Vietnam. We now see a resurgence of vivax malaria along the demilitarized zone of Korea as well as scattered cases of hantavirus infection. Is this also biological warfare?

The reviewers have no doubt that the respected aging Chinese scientists interviewed by the authors were true believers in what was once the official party line on biological warfare. None of them had modern training in epidemiology. Chinese medical science, at the time of the Korean War and for at least one decade thereafter, remained isolated from medical advances. It would seem more likely that the appearance of various forms of encephalitis, bacterial meningitis, plague, and cholera on and near the Korean battlefields were natural occurrences and were due to disruption of the social fabric of society, crowding, increased mobility of populations and their pests, breakdown of sanitation, and lack of pest control and adequate medical services.

Virtually every major military power, including the United States, Canada, and Britain, has experimented with and stocked chemical and biological warfare agents in the past.¹ Some such efforts go back to antiquity, as when a Polish general catapulted rabid dogs into a beleaguered city and wells were contaminated with dead bodies. Accusing adversaries of using biological weapons has been practiced not only by the Soviets and Chinese. Our government accused the Russians and Vietnamese of dropping trichothecene mycotoxins, derived from Fusarium and related fungi, on Laotian and Cambodian villagers as so-called "Yellow Rain." No proof that this happened was ever produced.^5-6 It is, however, established that the Soviets experimented with anthrax bacilli and even stockpiled them as potential weapons. They managed to have at least one accidental exposure of civilians in Siberia that resulted in many deaths.⁷ Allies also experimented with anthrax spores during 1942 and managed to experimentally contaminate an island off the coast of Scotland, making it uninhabitable for decades thereafter.⁸ General Shiro Ishi's group in Manchuria experimented extensively in 1940 with insect-bearing microbes. These experiments were of an offensive nature, and the Chinese, who possessed data on the experiments, and the Soviets tried and executed some of the culprits.⁹ Allied military scientists did indeed study insect-borne bacterial, parasitic, and viral zoonoses and still do. The 406th US Army Medical Laboratory in Japan and later medical researchers of the Southeast Asia Treaty Organization and the Armed Forces Research Institute of Medical Sciences in Bangkok, Thailand, investigated dengue fever, malaria, Japanese encephalitis, plague, rabies, hepatitis, and typhus. Many of their publications led to better prevention and treatment of these diseases.

The authors also allude to a number of insect experiments that do not seem logical, based on the level of knowledge that existed in 1950 as well as today. In many instances, insect vectors of particular diseases are species-specific to the pathogen (one insect species to one pathogen) or to a few closely related ones. Infecting an insect that is not the normal host of a pathogen may result in the pathogen being physically present but the unnatural insect host not being able to transmit it. At other times, the authors refer to reports from Chinese scientists of nonindigenous insects found following mysterious aircraft flights. There was no opportunity to verify those identifications, nor is there any indication of any understanding that the presence of these insects may have been due to less sinister causes.

Alleged examples of insect dispersion during periods when ambient temperatures were below freezing do not make much sense as a cause of epidemics. The authors are not convincing in their discussion of the use of "insect bombs" dropped by Sabre jets traveling at more than 300 mph as effective methods for distributing insects. For most arthropods, the impact alone would result in extensive mortality. How minute chigger mites could have survived the ordeal, survived an environment outside their normal range, and gone on to transmit scrub typhus is hard to conceive. Even the reported logistics of introducing infected mosquitoes do not seem plausible. There is no attempt to logically explain how this could be done. One of the reviewers once attempted to capture mosquitoes with a net, driving a car at 20 to 25 mph: none remained alive. Some of the insects allegedly found were pests of plants and thereby would have little role in the transmission of human disease. Although arthropods and arthropod-borne diseases have shaped military campaigns (eg, Napoleon's Russian campaign), the authors seem to attribute a lot more to the power of artificially reared and distributed arthropods than would seem realistic. That the authors do not include discussions with any US researchers from that era on the work in offensive or defensive biowarfare weakens their arguments. Natural epidemics are common during times of war; blaming an epidemic of dysentery and scattered cases of other human disease on US biowarfare insect research is not convincing.

Disturbing are the rather convincing and not new allegations that US military scientists, with the connivance of American occupation authority, harvested data from criminal Japanese experiments on Chinese and Allied prisoners in Manchuria. No Japanese doctor involved in the Manchurian experiments was ever indicted by Western war crimes courts. US officials must have protected Lieutenant General Shiro Ishi and his senior officers from the hangman, for he lived out his life span as a respected member of the Japanese academic medical community. He most certainly was responsible for hundreds of deaths at the infamous Unit 731 in Manchuria.¹⁰

This book makes interesting reading but may only confuse historians studying the Korean campaign, a bloody conventional war that was waged by the United Nations to defend South Korea from an invader who, even now, presents a threat to us all.