In a way, it is good that the Bataan Campaign of 1942 ended when it did. In the 1990s, newly discovered documents revealed a Japanese plan for the use of biological warfare against the Fil-Am forces on Bataan.
The infamous Imperial Japanese Army’s Unit 731 in Manchuria was probably the source of the development and supply of the deadly weapons. If you’ve never heard about Unit 731 you will be shocked to find out what happened there. It’s not for the faint of heart, but knowing about it will help to ensure that it doesn’t happen again, anywhere! A 19 minute 30 second video, not related to Bataan, outlines the horrific operations at Unit 731:
Unit 731 Japanese Torture & Human Experiments (Warning/Babala! Graphic images and discussion) https://www.youtube.com/watch?v=XCkGiiabV40
In the Research Library of the Japanese Defense Agency in Tokyo, Ika Toskija and Yoshimi Yoshiaki discovered documents in the early 1990’s which indicated that Imperial Japan planned to use biological weapons in the Philippines against the Fil-Am troops on Bataan.
Information from various sources indicates beginning in March, 1942, after Japanese forces had been quite bloodied on Bataan by the stubborn Fil-Am defenders, they planned to release 1,000 kilograms of plague-infected fleas. Another source indicates the plan called for release of 200-pounds of fleas carrying the plague, about 150 million insects, in each of ten separate attacks against Bataan’s defenders.
But Bataan fell before the plan could be implemented. There’s no ready detail on all the elements of this plan, and what level of authority approved the use of such a weapon – it was probably approved at echelons above the Japanese commander in the Philippines, General Homma. It is not known who if anyone requested it either, whether from Japanese forces in the Philippines or elsewhere. Thankfully the Fil-Am forces and many civilians on Bataan were spared this biological scourge.
Nevertheless, Japan used biological weapons tested on victims at Unit 731 elsewhere, specifically in China as retaliation for Chinese support of the Doolittle Raiders who attacked Japan with B-25 medium bombers on 18 April 1942.
The bombers were launched from the aircraft carrier USS Hornet and were to recover in China after they attacked Japan. The Japanese were enraged their homeland had been attacked, and the rage was focused on China where most of the raiders made their escape.
from mid-May through September, 1942, the Imperial Japanese conducted Operation Sei-go in China in retaliation for the support to the Doolittle raiders, and also to seize airfields to prevent future attack on Japan. In June and July of 1942, Japanese forces used aircraft to deliver cholera, plague and dysentery, as part of Sei-go. An estimated 10,000 Chinese were killed by these agents. But even the Japanese could not contain the death to the Chinese – when the wind shifted some of the dropped pathogens fell upon their own forces; other troops moved into areas where the diseases had been sown. As a result, 10,000 Japanese soldiers were affected -1,700 of them died, mostly from cholera.
The Japanese never really gave up on use of biological weapons during the war, though their efforts were largely frustrated. In 1944, after the fall of Saipan, there was a plan to send a submarine to the island to land teams to spread biological agents against American forces. But the submarine was reportedly sunk before it could accomplish the mission.
In 1945, another plan was to use gliders with pathogens and send them into Iwo Jima, but encountered problems getting the gliders from the Japanese Home islands to Matsumoto Airfield near Harbin, Manchuria, where presumably Unit 731 would have filled them with the nasty bugs. Use was contemplated in the battle for Okinawa, but did not occur.
Another 1945 plan was to make a biological warfare attack by submarine on the US west coast called Operation Cherry Blossoms at Night. The planned attack date was 22 September 1945, to use aircraft and even a landing party to spread the pathogens, but the Japanese surrender on 15 August 1945 kiboshed that venture before it could even get started.
War is a terrible thing, and as bad as it is, there are fiendish people who would make it even more terrible, terrifying, lethal and deadly, even at the expense of the innocent. May God help us to limit this destructive impulse such as is revealed in the horror of Unit 731 and the Imperial Japanese plan to use biological weapons on Bataan.
Lockwood, Jeffrey A. Six-Legged Soldiers: Using Insects as Weapons of War, page 119
Monahan, Evelyn. All This Hell: U.S. Nurses Imprisoned by the Japanese, page 138
Unit 731, Wikipedia page, at: https://en.wikipedia.org/wiki/Unit_731
Unit 731, at: http://www.unit731.org/
Unit 731: One of the Most Terrifying Secrets of the 20th Century, at: https://www.mtholyoke.edu/~kann20c/classweb/dw2/page1.html
Plague, Wikipedia entry, at: https://en.wikipedia.org/wiki/Plague_%28disease%29
Tsuneishi , Keiichi, “Unit 731 and the Japanese Imperial Army’s Biological Warfare Program,” at http://www.japanfocus.org/-tsuneishi-keiichi/2194/article.html
Zhejiang-Jiangxi campaign, wikipedia entry, at: https://en.wikipedia.org/wiki/Zhejiang-Jiangxi_campaign
Operation Cherry Blossoms at Night, Wikipedia entry, at: https://en.wikipedia.org/wiki/Operation_Cherry_Blossoms_at_Night
Selected Images from other sources
Doolittle Raid launch, at: https://en.wikipedia.org/wiki/Air_raids_on_Japan
Sinking Japanese submarine crew, at: http://plhb.tripod.com/p2.html
Japanese glider, at: http://www.yankee-yankee.com/stosil3.htm
I-400 sub and aircraft, at: http://www.britmodeller.com/forums/index.php?/topic/8856-tamiya-1350-ijn-submarine-i-400/page-2