Project Fu-Go: Japan’s Pacific War Balloon Counter-Offensive

Military history, Regional History

IN the latter stages of the Second World War, Japan, under pressure from American and Allied bombing raids on its territory, devised a novel fight-back strategy against the invaders. The strategy devised by the Japanese military high command, was certainly an unorthodox one and one signifying the increasingly desperate position of Imperial Japan in the global war.

By the second half of 1944 the Japanese military situation was unravelling fast…serious Japanese army and navy reversals in the Pacific theatre, Japan had lost its aircraft carriers, the earlier submarine raids in California and Oregon had been largely ineffective, and morale at home among the Japanese citizenry was flagging[1]. As the tide of the Pacific War was turning against Japan, the US targeted key cities of the Japanese home islands – from June 1944 to the Japanese surrender in August 1945 America unleashed a systematic, strategic bombing campaign (from bases in China and Micronesia) with long-range B-29 bombers causing extensive damage and destruction in Tokyo, Yokohama, Nagoya and Kobe, as well as a host of smaller cities❈.

The Japan military command in response devised a plan, the result of Project Fu-Go – to attack North America using hydrogen gas balloons, fūsen bakudan (literally “balloon bomb”). These “fire balloons” had incendiary bomb devices attached to them, and the idea was to release them from Japan, using the jet stream to carry them the 5,000km across the Pacific Ocean and destroy towns, farmland and forests in the US and Canada[1]. The mechanism constructed was a deceptively simple but clever device to “automate the flight and release the explosives” at a given point and altitude[2].

Japanese scientists had conducted atmospheric experiments from western Japan to eastern Japan, charting the pattern of late autumn/winter jet streams. The tests revealed a particularly strong air current in the Pacific at 30,000 feet✠. The first balloon weapons were released in November 1944 (at the same time that American B-29 missions started taking a more devastating toll on the Japanese homeland). The fire balloon journey took between 30 and 60 hours to reach the west coast of North America, however it has been estimated that about only one in nine of the balloons made it to America (an estimated 1,000 out of 9,000 launched from Japan)[3]. But the number that made the journey is very imprecise…US researchers after the war discovered or accounted for at least 342. It is believed that many more landed on the American mainland but they have not been detected yet owing to being located in remote, unpopulated parts of the country[4]. This is even more likely to be the case in the much sparser populated western Canada.

The first sightings of the strange hydrogen balloons on the American west coast were puzzling to the locals. Their origin was also a puzzle for the authorities until US geologists made tests of the sand recovered from the ballast bags which traced it back to Japan and the beaches of Honshu. Many Americans were still doubtful that the balloons had floated all the way from Japan, speculating that they had been transported by Japanese submarines and secretly unleashed on the North American west coast[5].

The American response to Fu-Go
The seemingly capricious nature (and innocuous appearance) of the fire balloons, to the American authorities, might not initially have seemed to pose much of a danger. Washington (DC) however did take it seriously…there was concern about the possibility of forest fires breaking out in the western regions of Canada and the US¤, and especially worrying to the US was the prospect of the Fu-Gos carrying biological weapons (which it knew the Japanese had been trying to develop)[6].

Once the source of the balloon weapons was established, the US government through its newly formed Office of Censorship put a watertight security blanket around the incidents. This starved the Japanese military of vital intelligence on the results of the balloon offensive, so Tokyo had no idea of whether the attacks were successful or not. US fighter pilots were engaged to intercept the incoming balloons but the results were at best marginal (one score only of the Fu-Gos were shot down)[7].

Klamath Falls, Fu-Go fatality site

The only known WWII fatalities occurring on contiguous US territory
The information blackout on the Japanese balloon attacks also extended to American civilians…this was to have a solitary tragic consequence late in the war. In May 1945 a picnicking group of adults and Sunday school children discovered one of the grounded fire balloons in countryside near Bly in southern Oregon. Their curiosity about the strange balloon led them to pick up the still live weapon…as a result a pastor’s wife Elsie Mitchell, her unborn child and five children aged 11 to 14 died instantly from a huge explosion. The seven unlucky victims were the only known American civilians killed by enemy action in the course of the war following Pearl Harbour[8]. After the fatal incident the Office of Censorship issued a public alert about the fire balloons, warning citizens to stay clear of them.
Heavily forested Southern Oregon countryside

The Bly incident was the solitary lethal attack on sovereign soil of the US mainland in the course of the World War. The only other damage from the Japanese fire bombs was to property…one Fu-Go incendiary struck a nuclear weapons plant in Hanford (Washington state), temporarily blacking out the plant which was manufacturing plutonium for use in the August 1945 atomic bomb attacks on Japan which ended the war.

Cessation of the fire balloon attacks
The uncertainty of not knowing how effective the balloon weapons were, did not inhibit the Japanese military from trying to exact propaganda value from the situation. News bulletins emanating from Tokyo broadcast a steady supply of “fake news” (as much for domestic consumption to boost morale)…announcements proclaimed that the floating incendiaries had claimed 10,000 US casualties, that the attacks had resulted in general alarm within the American population…they also issued a threat that Japanese troops were about to invade North America[9].

In April 1945 the Allied forces succeeded in blowing up two of Japan’s main hydrogen plants…this resulted in a scarcity in the ingredient needed for the fire balloons. This blow to the production of balloon weaponry, added to a growing realisation by the Japanese commanders that the attacks has not been a success relative to the resources expended, sealed the fate of the Fu-Go program[10].

PostScript 1: A balloon-scattered continential landscape
American Air Force writer Robert Mikesh described the Japanese fire balloons campaign as the world’s first intercontinental weapons delivery system. In six months in 1944-45 thousands of fire balloons were dispersed across the eastern Pacific and parts of North America. For most of the projectiles their fate was a watery grave but in the 70 plus years since the end of WWII the remnants of Fu-Gos have been found, strewn across the continent – as far east as Michigan and the Great Lakes, as far south as Mexico, and as far north as Alaska and Yukon.

PostScript 2: Canada’s fire balloon fields
Some of the balloon bombs were found in disparate locations like Hawaii and the Aleutian Islands, and one in British Columbia as recently as 2014. Canada in fact was as equally susceptible as the US to the latent dangers of the fire balloon attacks, much of the western coast and all of the northern part of the country comprises dry, forested land. At least 57 Fu-Gos were discovered across the Canadian west during those six months of the campaign (in Yukon, the Northwest Territories, Saskatchewan, Alberta and BC). From the recollections of some Canadians who experienced close encounters with unexploded balloons, it is somewhat of a miracle that there were not more fatalities of the balloon weapons that the seven in Oregon[11].

Fu-Go landing sites
(Source: National Geographic) Two of the fire balloons actually drifted back westward & landed on Honshu island!

▦ See also related blog, MAY 2018 on USA/Japan conflict in World War II: Project X-Ray: Bat Raiders over Honshu, America’s Other Secret Weapon in the War against Japan

⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯⌯
❈ the first US air raid on Japan had been in April 1942 – known as the Doolittle Raid – an isolated strike on Tokyo (primarily) intended as retaliation for Pearl Harbour four months earlier, and to probe Japan’s vulnerability to air attack
✠ this was the discovery of one particular Japanese meteorologist in the 1920s – Wasaburo Oishi
¤ a chilling recent echo of this was al-Qaida’s 2012 online urging of jihadists to plant ember bombsin American forests (Carroll 2014)

[1] R Carroll, ‘How Japan’s fire balloons took the Second World War to America’s soil’, The Guardian, 31-Oct-2014, www.theguardian.com
[2] S Lehman, Japan’s Secret WWII Weapon: Exploding Balloons’, Gizmodo, 13-May-2014, www.gizmodo.com.au
[3] its purpose hoped to provide an inexpensive way to shift the war’s focus onto sovereign American territory, ‘Fire balloon’, Wikipedia, http://en.m.wikipedia.org
[4] J Rizzo, ‘Japan’s Secret WWII Weapon: Balloon Bombs’, National Geographic, 27-May-2013, www.nationalgeographic.com
[5] RC Mikesh, ‘Japan’s World War II Balloon Bomb Attacks on North America’, Smithsonian Annals of Flight, no 9 (1973), www.sil.si.edu; ‘Fire balloon, op.cit.
[6] Rizzo, loc.cit.
[7] Lehman, loc.cit.
[8] ibid.; Rizzo, loc.cit.
[9] ‘Six killed in Oregon by Japanese bomb’, (‘This Day in History’, 1945), www.history.com. Seven in fact died including Mrs Mitchell’s unborn child
[10] Mikesh, op.cit.
[11] For instance one Saskatchewan youngster in 1945 accidentally stepped on a collapsed fire balloon which failed to detonate, S Brace, ‘Japanese bombs landed in Saskatchewan 71 years ago’, (Saskat News), 11-Feb-2016, www.cba.ca