Evidence mounts for biological attacks in Korean War, aided by know-how of notorious Japanese unit

On Dec 6, 1952, while the Korean War was raging, US Marine Corps Colonel Frank H. Schwable made a confession that shook the world.

"I do not say the following in the defense of anyone, myself included, I merely report as an absolutely direct observation that every officer, when first informed that the United States is using bacteriological warfare in Korea, is both shocked and ashamed." he said.

Schwable was among the 38 US flyers, including 36 US Air Force officers, who had been shot down and captured by the troops from the Democratic People's Republic of Korea and China. All confessed to their roles in missions that involved dropping germ-containing bombs on inhabited villages. Upon returning to the US after the war, all retracted their confessions, claiming that they had been tortured or indoctrinated during their captivity.

"While the assumption of some level of coercion is important in evaluating any prisoner's testimony in any setting, the validity of a witness' testimony ultimately lies in what can be proven, with some degree of confidence, in what they say," said Jeffrey Kaye, a clinical psychologist-turned-researcher with a specialty in the evaluation of torture victims. He was also the author of the 2016 book Cover-up at Guantanamo: The NCIS Investigation into the "Suicides" of Mohammed Al Hanashi and Abdul Rahman Al Amri.

After having pored over the "original, highly-detailed and hard-to-access" prisoners-of-war confessions, Kaye believes that they were "internally consistent and mutually corroborating".

One example concerns the depositions given by Colonel Schwable and two other US flyers－Major Roy H. Bley from the Marine Corps and Colonel Walker Mahurin from the Air Force. All stated that the Joint Chiefs of Staff gave the order to proceed with the germ warfare campaign in October 1951, and both Schwable and Mahurin emphasized the experimental nature of the use of biological weapons, or BW, in the initial months of its use in the war.

In March 2010, Al Jazeera English news program People& Power investigated the BW allegations, uncovering a declassified top secret document in the US National Archives which showed that in September 1951, the US Joint Chiefs of Staff issued orders to start "large scale field tests … to determine the effectiveness of specific BW agents under operational conditions".

Intensive interrogation

In fact, upon their return in the US, the repatriated Korean War prisoners who had admitted to participating in germ warfare were subjected to intensive interrogation by CIA personnel and threatened with court martial for treason, according to Daniel Barenblatt, author of A Plague Upon Humanity－The Hidden History Of Japan's Biological Warfare Program. The book delves into a dark post-WWII chapter which saw Washington decision-makers and General Douglas Mac-Arthur's occupation authority in Japan granting immunity to former members of the notorious Unit 731 of the Imperial Japanese Army, in exchange for information of Japanese BW experiments.

This information had been gained through the many germ attacks the unit launched all over China between 1932 and 1945, sometimes referred to as "trials", and through human experiments including vivisections, conducted at the unit's headquarters in Pingfang district in Harbin, a northeastern Chinese city.

In a 2010 interview with The Telegraph, Masataka Mori, history professor at Japan's Shizuoka University, said that after the outbreak of the war, he was told by several former Unit 731 members that Shiro Ishii, their former head, had traveled to the Republic of Korea with two of his top researchers to "advise the Americans on strategy". The claim was repeated in Japan's Asahi newspaper in March 1952.

Mori, who later traveled multiple times to the DPRK to research the subject, also noticed "striking similarities between the disease and weapons used by the Japanese military in China and those said to have been deployed by the United States against targets in northern Korea", according to the British newspaper.

Kenneth Enoch, one of the captured US flyers, told his interrogators that he had been ordered to report the germ bombs as ordinary "duds" at debriefings "in order to maintain secrecy". In the same article from The Telegraph, the reporter who had traveled to the DPRK was told by a witness-interviewee that the bombs that killed his father in the winter of 1952 "had opened－rather than detonated as conventional weapons would have done－after hitting the ground and released thousands of insects".

According to a 1952 study produced by US Air Force historian Dorothy Miller, by October 1950, "seven BW agents had been judged feasible for use". The study, a top secret document declassified with some deletion in 1978, also noted that near the end of 1951, "the development of feather bombs… made possible an immediate capability against cereal crops".

In their 1989 book Unit 731: The Japanese Army's Secret of Secrets, British researchers Peter Williams and David Wallace cited the testimony of a British platoon sergeant pointing to possible US adoption of the Ishii-esque way of infecting through feather spreading.

Along with all UN troops in headlong retreat from a major Chinese offensive into the DPRK in November 1950, the sergeant with the Middlesex Regiment saw "men in unmarked fatigues wearing gloves, parkas and masks going house to house, pulling feathers from containers and spreading them around". This was one month after the Chinese People's Volunteer Army joined the war, known in China as the War to Resist US Aggression and Aid Korea (1950-53).

In March 1952, then Chinese premier Zhou Enlai sent a telegram to the UN Secretariat, detailing claims of BW attack by the US Air Force. Between the ensuing June and August, the International Scientific Commission for the Facts Concerning Bacterial Warfare in China and Korea supported by the Helsinki-based World Peace Council, conducted investigations in the DPRK and northeastern China. Made up of leading experts from Britain, France, Italy, Sweden, Soviet Union and other countries, the commission was headed by world-renowned British biochemist and science historian Joseph Needham, who had been head of the British Scientific Mission in wartime China, during a time when Unit 731 and its branches were launching biowarfare across the country.

Although allowed access to four of the US POWs who confessed to BW, the commission made it clear in its 1952 report book that "the ISC conclusions were based purely on the empirical evidence of physical examinations, retrieved physical evidence, physical analysis and interviews with eyewitnesses".

And having interviewed hundreds of witnesses whose testimonies were "too simple, too concordant and too independent"－to quote from the ISC report－to be doubted, "the Commission has no option but to conclude that the American Air Force was employing in Korea (DPRK) methods very similar to, if not exactly identical with, those employed to spread plague by the Japanese during the World War II".

In a 1986 interview, nine years before his death, 86-year-old Needham said that he was "100 percent sure" that the BW allegations were real and accurate. The scientist, whose own academic integrity was rarely questioned, seemed to be keenly aware of the dismissal the ISC report had encountered both upon its issuance and in subsequent years.

Writing in 2008, US researcher Milton Leitenberg questioned the validity of the BW claim by pointing at the winter season that alleged attack by insect-borne BW took place. "The reports (by Chinese and North Koreans) stated that insects were found on snow, but there they would simply freeze and die," he said.

However, back on May 6, 1947, General Douglas MacArthur, commander of the UN troops during the Korean War, sent a top secret radiogram to the War Department's General Intelligence Division. Trying to persuade Washington to enter the secret deal with Unit 731 scientists, MacArthur stated that the unit chief "claims to have extensive theoretical high-level knowledge including strategic and tactical use of BW on defense and offense, backed by some research on best BW agents to employ by geographical areas of Far East and the use of BW in cold climates".

In 1998, Yasuo Naito, a reporter for the right-wing Japanese newspaper Sankei Shimbun, claimed that he found some documents from Soviet archives in Moscow detailing an elaborate hoax to manufacture false evidence of US biological weapons attacks.

The documents were cited by Kenneth Osgood, professor of history at Colorado School of Mines, in his March 29 article for The Washington Post. Calling what he dubbed the germ warfare campaign by the Chinese and the Soviets "one of the biggest lies of the Cold War", Osgood wrote, "Historical research after the collapse of U.S.S.R. confirmed as much. 'The accusations against the Americans were fictitious,' the U.S.S.R.'s Council of Ministers admitted in secret deliberations in 1953."

Barenblatt was not impressed. "Leitenberg and another US researcher Kathryn Weathersby, both of the Cold War International History Project at the Woodrow Wilson Center, published the Naito document the same year they were allegedly discovered, and a few months before the release of the first book published in the West that's entirely devoted to Korean War US germ warfare evidence since the ISC report of 1952."

In the book The United States and Biological Warfare: Secrets from the Early Cold War and Korea, Canadian researchers and historians Stephen Endicott and Edward Hagerman argued that the accusations against the US were true.

"Naito has never provided archival registry or specific file identification for the alleged documents, which, for more than two decades, have only been available as material transcribed from hand copies of the originals, with no photocopies or photographs provided," Barenblatt added.

"This is with the notable exception of one photographed Mao-to-Stalin telegram, which, together with a Stalin-to-Mao reply cable that was also released and photographed and is not in the Naito batch, is consistent with and affirming of the charges of US germ warfare being truthful. The texts show Mao and Stalin's belief in the accuracy of the biowarfare reports, and in the need to protect civilian populations."

In February 2013, the CIA posted more than 1,300 items online as part of their "Baptism by Fire" document release commemorating the 60th anniversary of the start of the Korean War, including two dozen 1952 reports by CIA analysts on intercepted radio communications from Communist forces describing BW attacks by US airplanes.

In an intercept dated Feb 26, 1952, an unidentified Chinese unit reported: "Yesterday it was discovered that in our bivouac area there was a real flood of bacteria and germs from a plane by the enemy. Please supply us immediately with an issue of DDT that we may combat this menace."

"These messages were real-time quotes. These people (the Chinese and the North Koreans) weren't faking it－they didn't even know that they were being overheard. The messages also show that the Communist authorities were doing their medical due diligence on reports of BW attack," said Kaye, referring to another intercept in which a DPRK sanitation officer was sent to what was believed to be an attack site and reported back that the flies "were not caused from the bacterial weapon but from the fertilizer on the place".

The CIA report analyzing this particular intercept goes: "This is the first observed instance in which a Communist unit has investigated and entered a negative report on an alleged American use of BW agents", indicating that there were other instances of such investigation that had produced positive conclusions on the presence of BW agents.

"Let's not forget that during WWII, the Chinese was subjected to the biggest biological attacks in human history. Their military and scientists, consequently, were anything but incapable of identifying a BW attack," said Kaye.

Reflecting on the fact that no written order for the BW attacks or after-report of their effectiveness has ever been found, Kaye called for more openness from the US government, which has been aggressively "redacting files and withholding information".

"On the other hand, it was typical practice in the US military that orders that might be construed as highly controversial or secret should not be written down but only transmitted orally," he said, referring to Colonel Schwable's description of a verbal order to carry out missions to spread cholera, typhus and yellow fever as one that had come all the way from the Joint Chiefs of Staff.