Japan now stood bereft of essential supplies. They were not so much short of military equipment as of the essentials needed for day-to-day life, including fuel oil. General Tojo Hideki became the Japanese Premier in October 1941, and realized at once that the position of his nation was desperate. He set 29 November as the date on which Japan would take military action against the United States, if no agreement was forthcoming. The United States, meanwhile, was hoping to inveigle Japan into entering the war and knew that the mighty American fleet moored in Pearl Harbor would be more than a match for any attempted invasion of territory by Japan. The intelligence service had heard that one of the targets would be Pearl Harbor; crucially, these revelations were never passed to the military commanders in Hawaii, so no preventive action could be taken. Moreover, Britain had recently perfected a transponder radar system called IFF (Identification, Friend or Foe) which they offered to the United States Army Signal Corps, but they turned it down. According to their leaders, they did not need anything from the British: American systems were best.
The attack, when it came, was unexpectedly from the air and launched with overwhelming force. Military strategists had expected Japan to invade countries to obtain her vital supplies, and the warships in Hawaii were ready to sail out to repel them when they did; nobody had imagined that Japan would instead annihilate the American fleet.
On the morning of 7 December 1941, a radar operator at the Fort Shafter radar station on the island of Oahu saw a large signal appearing on his screen. He asked a private stationed with him to look, and both agreed that there were a large number of aircraft about 130 miles (210km) away and approaching fast. Their superior officer was 1st Lieutenant Kermit A. Tyler, who listened carefully to their reported sighting. And then he reached his fateful decision. A flight of American B-17 bombers was due in that day, and he guessed this must be them. He was wrong: over 180 Japanese fighters, torpedo planes and bombers were heading to Hawaii at top speed. The opportunity to prepare or take cover was lost.
Six Japanese aircraft carriers were within range, and seemingly endless waves of planes had taken off to join forces against Hawaii. Two massive attacks then followed; 3,500 United States personnel were killed or severely wounded and 18 ships of the Pacific Fleet were sunk or badly damaged. More than 350 aircraft were destroyed. Further damage was done by scores of top-secret Japanese midget submarines that penetrated deep inside the port. Every one of the eight United States battleships was sunk; some 1,200 sailors were killed when just the USS Arizona was attacked. The United States lost her battleship fleet in the space of 2 hours. The Japanese attack was a complete success and a triumph of top-secret planning.
Much of the technology used in this audacious raid would have a far-reaching influence throughout the course of the war and beyond. Midget submarines were a particularly successful secret weapon. Pearl Harbor saw their first use in World War II but they were also used to great effect by the British and Italians.
The technology developed during World War II for small submarines is still in use to this day, often in unexpected applications. Tourist submarines some 32ft (10m) long are in use around the world, carrying people to see the wonders of life beneath the waves. Recently, secretly constructed submarines (some up to 98ft, 30m, long) have been discovered in Central American waters, where they are used for present-day drug smuggling.
Contrary to what we are so often told, the Pearl Harbor attack was no surprise to the United States government — it was launched after much provocation, and after copious warnings; it had even been detected by radar. Whatever else one might argue, it was not an unprovoked attack from an unexpected quarter, though the operation was a triumph of top-secret military planning.
The United States had their best code-breakers assigned to the difficult task of following the Japanese plans. They were systematically decoding their top-secret messages, and they soon learnt of a plan to lure the remaining American ships into a trap at Midway Island. In June 1942 in the battle of Midway the United States successfully turned the tables by sinking four Japanese aircraft carriers and a heavy cruiser in exchange for the loss of one aircraft carrier and a destroyer. This was the turning-point in the Pacific, and from that time onwards the Japanese headed steadily to defeat.
The secret weapons that were developed by the United States against Japan, and vice versa, included some of the most fanciful ever seen in war. The Japanese resolved to launch incendiary attacks against the United States, and manufactured some 9,000 hydrogen balloons to which they fitted small incendiary weapons that could burn for over an hour and 33lb (15kg) of high explosive anti-personnel bombs. The plan was to launch them into the high-altitude jet-stream — which the Japanese had just discovered — so that the weapons were carried across the Pacific to North America. The balloons were made of paper and were assembled by young women, mostly acting students from nearby schools. The washi paper for the balloons was made from large sheets stuck together with ‘devil’s tongue’ gel made by boiling the roots of arum lilies. Virtually the entire stocks of the arum root gel disappeared from the stores, partly to feed the balloon industry, but also because it had a pleasant taste and was being consumed by the students in copious quantities. Starting in November 1944, the Special Balloon Regiment established under the Imperial Japanese Army released a continuous stream of these balloons from Ibaraki Prefecture, on the western side of Honshu.
Unlikely as it seems, the ruse worked; most of the balloons burst or deflated, landing in the sea, but over 1,000 of these secret weapons reached North America and a quarter of them caused damage, mostly small forest fires. The first reports of the fireballs descending from the skies were dismissed as farmhand gossip, but towards the end of 1944 the authorities realized what was happening. Some of the balloons landed intact and were examined by the military. The payload contained magnesium as an incendiary device, partly to set fire to the balloons on landing, but also to ensure that the device was consumed in the blaze, so that the Americans would not discover the true nature of these strange balloons.
However, the balloons produced minimal interference with the conduct of the war, and once the nature of the weapons had been discovered, many were shot down by warplanes in mid-flight. A secret agreement was made with newspaper editors, so that reports of successful attacks were never published, and the Japanese could not find out how successful their balloons had been. After five months had passed without any news of damage appearing in the American news media, the Japanese became discouraged and discontinued their attacks. In reality, 285 balloon bomb incidents had been reported and some of the balloons reached as far as Michigan. One was found by a group of holidaymakers in the Oregon woods, all of whom were killed when they tried to move it and the anti-personnel mine exploded.
The United States were working on their retaliation with equally bizarre plans. A dentist (and inventor in his spare time) named Lytle S. Adams proposed to send a squadron of B-24 bombers to destroy Osaka, Japan. Each plane would carry 100 incendiary shells — and Adams had a unique twist to the proposal for a raid: the weapons would contain not bombs but bats. He argued that the bats would home in on the wood and paper buildings that were a feature of that ancient Japanese city. Each bat would carry a small incendiary charge, strapped securely in position. Once they had settled under the eaves or tucked themselves away in the roof spaces of buildings in Osaka, the fuses would light the devices — and the city would be destroyed in a massive conflagration.