I. The Fu-go Project


The confidential study noted that the bags were made of sections of paper, layered and glued with a paste manufactured from konnyaku , a common potatolike vegetable. The bags, which measured a shade under thirty-three feet in diameter, were connected to the undercarriage by nineteen 49-foot shroud lines. The undercarriage contained a single-cell 2.3-volt battery, an altitude-control device, a ballast-discharging mechanism, a ring of thirty-two sandbags, and five bombs—including four incendiaries and one fragmentation. Each undercarriage carried a two-pound demolition block of picric acid designed to destroy the mechanism in midair after it had completed its mission. Finally each balloon bag carried a flash bomb attached to the undercarriage by a 64.5-foot fuse. When the undercarriage exploded, this long fuse would burn until it ignited the hydrogen, producing a brilliant airborne explosion.

The ordnance they carried suggested the balloon bombs’ primary strategic mission was to wage an incendiary war against the rich forests of the American Northwest. Upon impact, each fire bomb would disperse a flaming chemical and had the potential of destroying hundreds of acres of woodland. If the Fu-Go mission had been entirely successful, the Imperial Command would have unloaded fifteen thousand antipersonnel bombs and sixty thousand incendiary bombs on the United States. But although more than three hundred and fifty balloons were documented as having reached the continent, few caused any significant fire damage, for their targets were frozen and often snow covered. Only during the winter were the westerly winds powerful enough to sweep the balloons across the Pacific in the three days the craft could be expected to remain aloft.

But what if physical destruction was not the primary objective of the balloon bombs? Even the most idealistic of Japan’s wartime planners knew that their balloons could not destroy the American military machine. But as they observed the psychological effects of American bombing raids on their civilian populations, they became increasingly aware of how vulnerable a nation under stress could be. Enemy bombers coming out of the sky are fearsome weapons; but at least their coming can be seen and heard. The Fu-Go balloons, on the other hand, were capricious: they drifted silently, unpredictably, far beyond sight of the naked eye. Their bombs descended mysteriously, from an unknown, faceless enemy, presumably leaving their victims prey to hidden fears, to vague suspicions, and even to mass hysteria.

And they were mysterious, these weapons. After the balloons had dropped the last of their payload, they would ignite themselves in a celestial grand finale. This fashioned a blazing extraterrestrial phenomenon, and throughout the winter months of 1944-45, Western farmers and ranchers reported seeing bright, stationary fireballs in the skies, while, on December 8, 1944, the Northern Wyoming Daily News reported that a “Phantom Plane” was being sought after a series of explosions illuminated the night sky. The mystery was later solved when Naval Research Laboratory investigators determined that bomb and paper fragments found in the area had Japanese origins.

The balloons failed to inspire widespread panic but they did succeed in stirring grave fears among U.S. government officials, who foresaw the possibility of a disaster of unimaginable scope. One military historian, who believes the primary purpose of the balloon bombs was to spread fire, describes their “second most logical purpose” as the introduction of biological warfare. “The intense cold (minus 20 to minus 50 degrees Centigrade) at the altitude of the balloon flights,” wrote Cornelius W. Conley in the February/March 1968 issue of Air University Review , “would facilitate the transmission of bacteria, and disease germs affecting humans, animals, crops and forests could be transported.… It would be theoretically possible to infect the vast U.S. culcine (mosquito) population and establish a permanent endemic focus of an agent.”

Consequently, state health officers, veterinarians, agricultural agents, and 4-H Clubs were among those mobilized, under the code name “Lightning Project,” to be on the lookout for possible epidemics or poisonings. Decontamination squads were trained, and the government set up detailed procedures for collecting information, for dealing with reports, and especially for keeping a tight lid on the story.

There is no evidence that the Japanese loaded the balloons with harmful bacteria. General Sueki Kusaba and Technical Lieutenant Commander Kiyoshi Tanaka, leaders of the balloon bomb project, have consistently maintained that they never planned to engage in biological or chemical warfare.

The Fu-Go project ended early in April, 1945, after thousands of launchings. Historians have extolled American newspaper and radio editors for their discretion, which allegedly prevented the Japanese from knowing that their balloons were reaching the United States. On May 29, 1947, The New York Times declared: “Japan was kept in the dark about the fate of the fantastic balloon bombs because Americans proved during the war they could keep their mouths shut. To their silence is credited the failure of the enemy’s campaign.”