Last time we spoke about Operation Downfall. The Allies, under General Krueger, initiated a decisive campaign to clear the Japanese from Luzon. As they faced the entrenched Shobu Group, challenges included treacherous terrain and a resilient enemy. Simultaneously, Japan braced for an invasion, mobilizing reinforcements and devising defensive strategies to ward off the impending Allied assault. As July approached, General Yamashita’s forces prepared to execute a final breakout, but progress was hampered by relentless guerrilla attacks and adverse weather conditions. With Operation Downfall looming, Allied troops focused on strategic landings in Kyushu and Honshu, driven by a relentless determination to defeat the Japanese militarily. The intense battles of Luzon became a precursor to this monumental operation, marking a turning point in the Pacific War.

This episode is The Siege of Japan

Welcome to the Pacific War Podcast Week by Week, I am your dutiful host Craig Watson. But, before we start I want to also remind you this podcast is only made possible through the efforts of Kings and Generals over at Youtube. Perhaps you want to learn more about world war two? Kings and Generals have an assortment of episodes on world war two and much more so go give them a look over on Youtube. So please subscribe to Kings and Generals over at Youtube and to continue helping us produce this content please check out www.patreon.com/kingsandgenerals. If you are still hungry for some more history related content, over on my channel, the Pacific War Channel you can find a few videos all the way from the Opium Wars of the 1800’s until the end of the Pacific War in 1945.

Boy I have been waiting a long time to come to this point. One of the most significant events in human history that deeply affects us to this very day. Nuclear war is as much a threat today as it was during the cold war. The dropping of the Atomic bombs on Hiroshima and Nagasaki were deeply complicated events fraught with issues of morality. It goes without saying whether or not the bombs needed to be dropped, their actual impact on the surrender of Japan and so forth are still issues hotly debated to this very day. I have spoken on the issue countless times on my personal channel and podcast, but I figure to do this subject justice I will create a full episode for it. Thus in this episode we are going to just cover what happened, but rest assured I will come back to this later on.

As we last explored, following the successful invasion of Luzon in the Philippines, along with the fall of Iwo Jima and Okinawa, American forces began preparing for the final invasion of the Japanese Home Islands. This operation was codenamed Operation Downfall. One key initiative leading up to this invasion was a comprehensive air-sea blockade and bombardment campaign against Japan itself. Previously, we detailed the extensive firebombing and precision bombing efforts executed by General LeMay’s 21st Bomber Command. However, during this crucial period, the B-29 Superfortress bombers undertook a distinct operation under the codename Starvation. This single operation would be one of the largest factors that contributed to the surrender of Japan and its one most people have never heard of.

In July 1944, Admiral Chester W. Nimitz proposed a bold plan to use B-29 Superfortress bombers to mine the waterways surrounding the Japanese Home Islands. Although Generals Henry H. Arnold and Walter Hansell expressed concerns that this mining campaign could distract from the B-29's primary role as a strategic bombardment aircraft, they eventually agreed to assign one bomber group to focus on aerial mining when conditions permitted. On December 22, Hansell's 21st Bomber Command was directed to formulate a naval mining program aimed at executing between 150 to 200 sorties each month, which was set to begin in April 1945. However, by this time, General Curtis LeMay had taken command of the 21st Bomber Command. LeMay was notably enthusiastic about the idea and successfully recommended to Washington an upgraded mining program that aimed to deploy up to 1,500 mines each month using a full B-29 wing. LeMay viewed aerial mining in a different light than Arnold or Hansell, seeing it as a vital extension of strategic bombing. He recognized that most of Japan's war production materials, as well as a significant portion of its food supplies, were imported from regions such as China, Southeast Asia, and the Dutch East Indies. Japan's industrial heartland is primarily found on Honshu, its largest and most industrialized island, while Shikoku, another island, also lacks essential resources such as iron ore and high-quality coal. These crucial materials were sourced from Kyushu and Hokkaido, both of which are other Japanese islands. All these resources were transported by sea, so without easy access to raw materials, Japan’s industrial output would come to a grinding halt. The only aircraft capable of deploying mines effectively where they were needed were the B-29s. Areas such as the Inland Sea, the Sea of Japan, and the Korean Peninsula were out of reach for other Allied aircraft. Additionally, Allied submarines could only venture into these perilous waters with great risk. Notably, about 80% of Japan's merchant fleet utilized the Shimonoseki Strait, a critical waterway that separates Kyushu from Honshu. Understanding the strategic advantage of closing this strait, LeMay decided to allocate an entire wing of B-29s specifically to mine this vital route.

Brigadier General John Davies commanded the 313th Bombardment Wing, tasked with deploying approximately 2,000 naval mines each month into Japanese waters. The primary goals of this operation were to prevent essential raw materials and food supplies from reaching the Home Islands, hinder the supply and mobilization of Japanese military forces, and disrupt transportation routes in the Inland Sea of Japan. Between March 27 and April 12, Davies’ bombers targeted key enemy shipping bases located in Kure, Sasebo, and Hiroshima. They also focused on the Shimonoseki Strait, a narrow and strategically important waterway that links the Inland Sea with the Tsushima Strait. Notably, after these attacks, this strait was successfully closed for two weeks. On May 3 and 5, the 313th Bombardment Wing laid down a total of 1,422 mines in the waters surrounding the Shimonoseki Strait, as well as near major urban centers like Tokyo, Nagoya, Kobe, and Osaka. These efforts aimed to severely disrupt maritime commerce between Japan’s major industrial areas. Just a week later, the minefields expanded from the Shimonoseki Strait to include Kyushu, the southernmost of Japan’s four main islands, and northwest Honshu, the largest island containing Tokyo. By the end of that month, these mines were proving remarkably effective, accounting for the sinking of more ships than Japanese submarines. In fact, within the Shimonoseki Strait alone, 113 ships had been sunk.

Between June 7 and July 8, American forces expanded and fortified minefields along the western coast of Japan while also replenishing the existing minefields in the Shimonoseki Strait and the Inland Sea. During this effort, they successfully laid a total of 3,542 mines across 14 missions. The "total blockade" officially commenced on July 9 and continued until the end of the war. Throughout this period, American forces executed 474 sorties, dropping another 3,746 mines that replenished existing minefields and extended coverage to harbors in Korea. In total, Brigadier General Davies conducted 46 missions that laid down 26 minefields containing 12,135 mines. Remarkably, only 15 B-29s were lost during these operations. In turn, the mines accounted for the sinking or damaging of 670 Japanese ships, with a total loss of 1.25 million tons. This mining campaign effectively strangled Japanese industry, as the denial of essential raw materials to factories proved more disruptive than the direct bombing of the plants themselves.

Despite the clear vulnerability of Japan’s economy to disruptions in coastal shipping, Japanese authorities were alarmingly unprepared to address the threat posed by air-dropped mines. By August 1945, Japan had committed 349 ships and 20,000 personnel to counter the Starvation campaign, but these efforts were overwhelmingly ineffective. The shipping crisis escalated to such a degree that searchlights and anti-aircraft batteries were redeployed from urban centers to defend expected mining targets. Additionally, suicide boats were employed in desperate attempts to clear the minefields. Royal Navy historian S.W. Roskill commented on the situation, stating, “The blockade had, in fact, been far more successful than we realized at the time. Although submarines initially played a critical role in enforcing the blockade, it was the air-laid mines that ultimately strangled Japan.” Japanese officials shared this assessment. A director from a Tokyo steel company reflected on the situation, noting that the denial of essential raw materials to factories caused far greater disruption than the direct bombing of the plants themselves. This contradicted the views of US Army Air Forces experts back in Washington. In a striking remark after the war, a Japanese minesweeping officer told American forces, “The result of B-29 mining was so effective against shipping that it eventually starved the country. You could have likely shortened the war by starting this campaign earlier.”

Meanwhile, General LeMay continued his firebombing campaign against Japan. By the end of May, urban areas around Tokyo Bay had been devastated, prompting the 21st Bomber Command to shift focus westward toward the densely populated industrial complexes lining Osaka Bay. On June 1, 521 B-29s were dispatched to bomb industrial targets situated along the Yodo River, with an escort of 148 P-51 fighters. Unfortunately, an undetected thunderstorm struck en route, which meant only 27 P-51s reached Osaka, while another 27 crashed, and the remaining fighters had to return to Iwo Jima. Despite these complications, the B-29s bombed from altitudes ranging between 18,000 and 28,500 feet, successfully dropping 2,788 tons of incendiary bombs on Osaka. The attack resulted in the burning of 3.15 square miles, destroying 136,107 houses and 4,222 factories.

Four days later, on June 3, 530 unescorted B-29 Superfortresses launched a bombing raid on the city of Kobe. Of those, 473 aircraft targeted the city, resulting in the destruction of 4.35 square miles. This devastating strike led to the demolition of 51,399 buildings, while another 928 suffered significant damage. The raid, however, came with losses, as 11 bombers were downed, and 176 were damaged in the operation. On June 7, 449 B-29s returned to Osaka. Despite facing heavy cloud cover that restricted visibility, they managed to burn an additional 2.21 square miles of the city, destroying another 55,333 buildings.

By the conclusion of General Curtis LeMay’s maximum-effort area bombing campaign, the six most significant industrial cities in Japan, Tokyo, Nagoya, Kobe, Osaka, Yokohama, and Kawasaki, had been left in ruins. Major factories were either destroyed or severely damaged, while thousands of smaller household and feeder industrial units were consumed by flames. Casualty figures surged into six figures, leaving millions of people homeless. The evacuation of survivors further complicated efforts to secure labor for the factories that remained operational. Japan's air-raid protection system proved woefully inadequate to withstand a protracted siege by very heavy bombers. The system lacked sufficient organization, trained personnel, shelters, fire-fighting equipment, and facilities for relief and evacuation. Additionally, there was a significant deficiency in civilian indoctrination regarding emergency procedures. Under the relentless pressure of repeated major attacks, local Air Raid Precaution organizations collapsed, adding strain to an already overburdened imperial government. Japanese civilians, who had been conditioned by victory propaganda, displayed little of the discipline that helped German citizens endure years of aerial bombardment. As news of military defeats and the impact of B-29 precision strikes filtered into the great cities, residents began to lose confidence in their leaders’ ability to protect them or care for the victims of the attacks. Abe Motoki, the Minister of Home Affairs at the time, later remarked, “I believe that after the raids on Tokyo on May 23-24, 1945, civilian defense measures in that city, as well as in other parts of Japan, were considered a futile effort.” Regarding the operational cost of this campaign for the 21st Bomber Command, it was not considered excessively burdensome. Over the course of 17 maximum-effort incendiary attacks, LeMay dispatched a total of 6,960 B-29s, which dropped 41,592 tons of bombs. The losses amounted to 136 B-29s, averaging only 1.9% of the sorties, a rate significantly lower than what had been endured in earlier months, and quite acceptable by the standards of conventional strategic bombing.

Meteorologists predicted that the summer monsoon would keep Japan’s skies covered with clouds for most of the upcoming months, from June to August. As a result, LeMay shifted strategies under what became known as the Empire Plan. This approach prioritized targeting industrial and military sites during daylight hours when the weather permitted, while secondary cities that had sufficient industrial capability became targets for nighttime area attacks. This change meant that since no single target warranted a full four-wing maximum effort, multiple missions could be scheduled in a single day. Accordingly, on June 9, 110 B-29s attacked three aircraft factories located in Narao, Atsuta, and Akashi. The strikes successfully destroyed the factories in Narao and Atsuta, but an unfortunate miscalculation led to the bombing of the town near Akashi. The following day, June 10, a force of 280 B-29s, escorted by 107 P-51 Mustang fighters, targeted six distinct sites in the Tokyo Bay area. The mission yielded significant results, with all targets sustaining heavy damage. Finally, on June 15, 516 B-29s were dispatched for one last firebombing raid against Osaka and the neighboring city of Amagasaki. In this combined assault, 444 bombers dropped over 1,350 tons of incendiary bombs, incinerating an additional 1.9 square miles in Osaka and more than half a square mile in Amagasaki.

Starting on June 17, General Curtis LeMay’s firebombing campaigns began to focus on medium-sized secondary cities across Japan. On that day, 477 B-29 Superfortresses targeted the cities of Omuta, Hamamatsu, Yokkaichi, and Kagoshima, burning a combined total of six square miles in these urban areas. The success of this initial multi-target mission ensured the continuation of the program, establishing an operational pattern that would remain standard during the final weeks of the war. In total, multiple incendiary attacks were conducted on sixteen occasions, averaging about two missions per week. Between June 17 and August 14, American forces carried out 8,014 sorties, dropping a staggering 54,184 tons of incendiaries across 58 secondary cities. On June 22, 446 B-29s were dispatched to strike six targets located in southern Honshu, including the crucial Kure Naval Arsenal. In this mission, 382 bombers released 2,103 tons of bombs, inflicting heavy damage to these essential manufacturing facilities. Just four days later, on June 26, a force of 510 B-29s, accompanied by 148 P-51 Mustang escorts, targeted locations in southern Honshu and the nearby island of Shikoku. However, dense clouds over much of the area complicated assembly and forced many aircraft to attack targets of opportunity individually or in small groups. As a result, adverse weather conditions would delay subsequent daytime raids until July 24.

In the coordinated strike program that commenced in June, the decision to focus on either the Empire Plan or urban industrial targets was largely influenced by weather conditions. As the program took shape, the 315th Bombardment Wing (VH) became available for combat operations. This wing operated somewhat independently from the other bomber units, with its activities significantly guided by the specialized equipment of its aircraft. Authorized for deployment in the Pacific in December 1944, the 315th settled at Northwest Field, Guam, during May and June. Its commander, Brigadier General Frank A. Armstrong, Jr., was a seasoned veteran of the strategic air offensive against Germany. The B-29s of the 315th Wing differed in two key respects from those of other units. They were equipped with the AN/APQ-7 (Eagle) radar, a sophisticated radar system designed for bombing, instead of the conventional AN/APQ-13 radar. The latter had primarily served as a navigational aid. While crews had become adept at using the AN/APQ-13 for night or poor-weather bombing, it lacked the precision necessary for accurate strikes. The Eagle radar, however, offered significantly greater definition and, although it required a long bomb run averaging seventy miles, this was not considered a serious hindrance in the tactical context of Japan. To further enhance its night-bombing capabilities, the Superfortresses had been stripped of all armament except for the tail gun. This modification, along with the Eagle radar, clearly marked the 315th as a dedicated night-bombing unit. There were various proposals for the use of these specially equipped B-29s, including high-altitude bombing, area bombing, and aerial mining. However, by the time the 315th Wing was ready for combat, the 313th Bombardment Wing had already gained proficiency in aerial mining, while all wings had become adept at area bombing using the AN/APQ-13. Training for the 315th had focused heavily on night radar tactics, with less emphasis on visual bombing and daytime formation flights. It was evident that if the Eagle radar was to undergo a thorough scientific evaluation, it should be tested against a specific set of targets that were preferably large in size and located along the coastline. In the view of the 21st Bomber Command, the oil industry met these requirements perfectly.

The 315th Bombardment Wing initiated its specialized campaign on June 26 with a targeted strike against the Utsube Oil Refinery in Yokkaichi, the top-priority target. By August 14, the wing had conducted 15 additional missions against a total of 10 targets, which included various petroleum refineries and synthetic plants, such as the Maruzen Oil Company in Wakayama, Mitsubishi Oil Company in Kawasaki, and Nippon Oil Company plants spread across Akita, Kansai, Kudamatsu, and Amagasaki, as well as the Imperial Fuel Industry Company in Ube and Toa Fuel Industry in Wakayama. During the campaign, the 315th Wing dispatched a total of 1,200 B-29s, 1,095 of which successfully bombed their primary targets, dropping 9,084 tons of 500-pound general-purpose bombs deemed particularly effective against the scattered installations.

The increase in bomb load capacity was made possible by stripping the planes of unnecessary equipment and conducting bombing missions individually at night. As the crews gained experience, they were able to increase the average weight carried from 14,631 pounds during the first mission to 20,684 pounds by August 9. Despite concerns about safety from removing most of the aircraft's armaments, only four planes were lost and 66 sustained damage throughout the campaign. The 20th Air Force estimated that the B-29 attacks led to the destruction of approximately 6 million barrels of tank storage capacity, and the United States Strategic Bombing Survey (USSBS) reported that refining capacity had been reduced from 90,000 barrels a day in December 1941 to around 17,000 barrels. However, the strategic impact was more apparent than real, as many storage tanks were empty and refinery production had fallen to just 4% of capacity before the very heavy bomber campaign began. The lack of precise intelligence regarding the state of Japan’s economy had justified the emphasis on the oil program as a form of reinsurance. Nevertheless, the blockade had effectively severed the nation's oil resources, resulting in tankers remaining idle at the docks.

On July 1, Admiral Halsey’s 3rd Fleet departed San Pedro Bay to initiate the first preliminary strikes in preparation for Operation Olympic. This operation involved battleships and heavy cruisers conducting surface bombardments of industrial targets in eastern Japan, while lighter forces performed anti-shipping sweeps along the coast. Additionally, a fleet of submarines advanced ahead of Admiral McCain’s Task Force 38 to eliminate picket boats and establish lifeguard positions. At 18:15 on July 9, the force began its 25-knot approach toward the Home Islands, launching its first strikes against the Tokyo area at 04:00 on July 10. A total of 1,732 sorties were executed, targeting locations from Koriyama to Hamamatsu, dropping 454 tons of bombs and 1,648 rockets over Honshu with negligible opposition. American airmen reported the destruction of 109 enemy aircraft and damage to 231 during these strikes.

Following this, Halsey’s fleet moved north to bombard Hokkaido and northern Honshu, which were beyond the effective range of the B-29s and had previously evaded attack. At 05:59 on July 14, Rear-Admiral John Shafroth’s Bombardment Group Able, consisting primarily of three battleships and two heavy cruisers, was tasked with attacking the Kamaishi Works of the Japan Iron Company. By midday, Shafroth’s forces had opened fire on Kamaishi, marking the first surface bombardment of Japan by a hostile fleet in over 80 years. Between 12:10 and 14:19, a total of 802 16-inch shells, 728 8-inch shells, and 825 5-inch shells were expended, setting the town ablaze as key industrial and residential targets were hit and resulting in the sinking of one oil tanker, two barges, and one small ship in the harbor. Simultaneously, McCain’s carriers closed to within 80 nautical miles of Japan, launching 1,391 sorties against Hokkaido and northern Honshu to target railways, shipping, and airfields, again facing only light resistance.

In the ensuing strikes, American planes sank over 50,000 tons of shipping and naval craft, including the destroyer Tachibana, four minesweepers, eight naval auxiliaries, and around 20 merchant vessels, with significant losses occurring at Muroran and Hakodate. In addition, 25 enemy planes were destroyed, while American losses totaled 24 aircraft and 17 airmen, about half of whom were lost in combat. Task Force 38 launched another assault on July 15, executing 966 combat sorties that dropped 355 tons of bombs and expended 2,093 rockets. This operation resulted in the sinking of 65 vessels and damaging 128 others, as well as the destruction of 48 locomotives and damage to 28. Widespread destruction was inflicted on several facilities, particularly the Aomori–Hakodate railcar ferry system, which transported 30% of the coal between Hokkaido and Honshu. The strikes devastated the ferry system, sinking eight ferries, beaching eight more, and damaging two. In total, 70 auxiliary sailing colliers were sunk, and 11 were damaged, along with 10 steel freighters lost and 7 damaged. The ferry strikes were the brainchild of Halsey’s operations officer, Captain Ralph “Rollo” Wilson. “When the first action reports began to sift in,” Halsey related: He snatched them up and pored over them; the ferries were not mentioned. Later reports also ignored them. Rollo was sulking and cursing when the final reports arrived. I heard him whistle and saw him beam. “Six ferries sunk!” he said. “Pretty soon we’ll have ‘em moving their stuff by oxcarts and skiffs!”

Additionally, 20 city blocks in Kushiro were razed. The most significant outcome of these operations was the virtual severance of Hokkaido from Honshu. By the end of the raids, Halsey’s 3rd Fleet had achieved the sinking of 140 ships and small craft, damaging 235 others, and destroying 38 planes while damaging 46. Meanwhile, Rear-Admiral Oscar Badger’s Bombardment Group Baker, composed of three battleships, two light cruisers, and eight destroyers, was assigned to bombard Muroran. Between 09:36 and 10:25, this group fired 860 16-inch shells at the Nihon Steel Company and the Wanishi Ironworks, targeting both the coal liquefaction plant and coke ovens. This bombardment inflicted severe damage on those facilities and resulted in the destruction or damage of 2,541 houses in Muroran. As Hasley recalled “These sweeps and bombardments accomplished more than destruction. they showed the enemy that we made no bones about playing in his front yard. From now on, we patrolled his channels and shelled his coast almost every night that the weather permitted.” Additionally, Rear-Admiral James Cary Jones’ four light cruisers conducted a sweep along the east coast of Honshu to hunt for Japanese shipping; however, they reported no contacts during their mission.

Early on July 16, Task Force 38 retired east of Honshu to begin refueling and rendezvoused with Admiral Rawlings’ Task Force 37, which agreed to operate closely as an additional task group for Admiral Halsey. At 03:50 on July 17, the two task forces began launching strikes against central Honshu despite adverse weather conditions. The American forces executed 205 sorties targeting the Mito area, while British aircraft flew 87 sorties against airfields and railyards along the northwest coast of Honshu. Despite the bad weather, several small craft and locomotives were destroyed, though the operation resulted in the loss of nine aircraft and four airmen. Later that afternoon, Halsey detached Badger’s augmented Bombardment Group to attack Hitachi, a significant industrial and electronics-producing city. The 53-minute bombardment commenced in fog and rain at 23:14, during which 1,207 16-inch shells, 267 14-inch shells, and 292 6-inch rounds were expended against the Tago and Mito Works of the Hitachi Manufacturing Company, as well as the Yamate Plant and copper refining facilities of Hitachi Mine, resulting in severe devastation. On July 18, McCain’s two leading carriers launched a total of 592 sorties against Yokosuka, specifically targeting the heavily camouflaged battleship Nagato at the naval base. The attacks resulted in the sinking of one old cruiser, one minesweeper, one submarine, one incomplete destroyer, and three patrol vessels, in addition to damaging one subchaser, one old destroyer, and one old battleship. Although Nagato was hit multiple times and suffered heavy damage, it managed to stay afloat. Meanwhile, three carriers also targeted airfields and other opportunities in Tokyo, while Task Force 37 attacked a seaplane base at Kitaura and airfields at Nobara, Naruto, Chosi, Kanoike, Natori, and Kitakawa.

The recent raids resulted in the destruction of 43 enemy planes and damage to 77 others on the ground, along with the destruction of three locomotives and the derailing of four electrified train cars by rockets. However, the American forces incurred losses of 14 aircraft and 18 aircrew, as the 3rd Fleet flyers reported encountering the fiercest anti-aircraft fire they had yet experienced. Additionally, Rear-Admiral Carl Holden’s four light cruisers were detached during the night to sweep shipping off Sagami Bay and to target the radar site at Cape Nojima. On July 21, Captain Thomas Hederman’s Destroyer Squadron 61, consisting of nine destroyers, was assigned to conduct another anti-shipping sweep off Sagami Bay. Pursuing four radar contacts, the destroyers engaged targets at midnight on July 22, firing guns and torpedoes from 7,000 yards. This action resulted in the sinking of the 800-ton freighter No.5 Hakutetsu Maru and damaging the 6,919-ton Enbun Maru. In response, Japanese coastal artillery, the minesweeper W-1, and subchaser Ch-42 returned fire, but Hederman’s squadron successfully retired without damage. Although minor in scale, the Battle of Sagami Bay would ultimately be the last surface action of the war. Meanwhile, as part of Operation Barney, a planned submarine penetration of the Sea of Japan, nine submarines succeeded in sinking 27 Japanese merchant vessels and one submarine, totaling 54,786 tons.

On June 8, the submarine Barb commenced her twelfth patrol, tasked with terrorizing the Sea of Okhotsk using her newly installed 5-inch rocket launchers. Over the following weeks, Skipper Commander Eugene “Luckey” Fluckey executed successful rocket bombardments on Shari, Hokkaido, and targets in Shikuka, Kashiho, and Shiritoru on Karafuto (southern Sakhalin), also employing the submarine's deck guns to destroy 35 sampans in the town of Kaihyo To. Observing Karafuto trains transporting military supplies to ports, Fluckey devised a plan to intercept these trains. Engineman Third Class Billy Hatfield recalled how, as a child, he had placed nuts on railroad ties and watched as the weight of passing trains cracked them between rail and tie. Realizing this principle could be adapted, he suggested rigging an automatic detonator. Fluckey had many volunteers for the mission, including a Japanese POW, and carefully selected Hatfield and seven others, deciding against leading the shore party himself.

Just after midnight on July 23, 1945, Fluckey maneuvered Barb to within 950 yards of the Karafuto coast. Led by Lieutenant William Walker, the team launched two rubber rafts at 00:30. Before they left, Fluckey instructed them, “Boys, if you get stuck, head for Siberia, 130 miles north, following the mountain ranges. Good luck.” Upon reaching the shore, the Americans located the tracks and buried a 55-pound scuttling charge and battery beneath the rails, positioning it under a water tower they planned to use as a lookout. As Motor Machinist’s Mate First Class John Markuson climbed up, he unexpectedly found he was scaling a sentry tower, causing him to retreat without alerting the sleeping guard. When a train passed, the team dove for cover before resuming their work after it had gone by. Shortly after 01:30, Walker’s team signaled their return to Barb, which was now just 600 yards offshore. Fifteen minutes later, while the boats were halfway back, Fluckey heard the rumble of an approaching train. He hoisted a megaphone and urged the crew to “Paddle like the devil, boys!” At 01:47, a 16-car Japanese train struck Hatfield’s detonator, resulting in a massive explosion that sent debris soaring 200 feet into the air and reportedly killed 150 Japanese. Minutes later, all eight Americans were safely aboard Barb, which then slipped back into the night, having successfully executed the only amphibious invasion of Japan during World War II. Returning to the main action, Halsey aimed to eliminate the remnants of the Combined Fleet at the heavily fortified Kure Naval Base. Consequently, Task Force 38 began launching the first of 1,363 sorties against ships and airfields in Kyushu, Shikoku, and Honshu, ringing the Inland Sea at 04:40 on July 24.

A total of 599 tons of bombs and 1,615 rockets were unleashed over Kure, resulting in the sinking or damaging of 22 warships, which totaled 258,000 tons. Among the affected vessels were the battleships Hyuga, Ise, and Haruna; fleet carriers Amagi and Katsuragi; the escort carrier Kaiyo; heavy cruisers Tone and Aoba; as well as light cruisers Oyodo and Kitakami. In addition, another 53 vessels amounting to 17,000 tons were sunk at various locations, including Hiroshima Bay, Niihama, Bungo Channel, and Kii Channel. At Kobe, the incomplete fleet carrier Aso was also attacked and damaged. American Hellcats and Corsairs effectively swept aside Japanese aerial opposition, shooting down 18 enemy planes while destroying 40 aircraft and damaging another 80 on the ground.

Furthermore, around the Inland Sea, 16 locomotives were destroyed and five were damaged, while 20 hangars sustained damage. Three oil tanks were set ablaze at Kure and one at Tano. Additionally, four electric trains and a roundhouse were strafed at Hamamatsu, and various military installations, including barracks, warehouses, power plants, and factories around the airfields, received significant damage. Simultaneously, Rear-Admiral Rawlings’ Task Force 37 conducted 257 sorties against targets in Japan and the surrounding offshore areas, sinking the escort carrier Shimane Maru in Shido Bay, along with a number of destroyers, small escorts, and coasters. Meanwhile, Jones’ light cruisers swept through the Kii Channel before bombarding the Kushimoto seaplane base and airfields at Cape Shionomisaki during the night. Supporting these efforts, General LeMay dispatched 625 B-29s against seven targets in the Nagoya and Osaka areas, successfully inflicting heavy damage on all of them despite the spotty weather, marking this as the last major attack on the Japanese mainland during the war, as two weeks of cloudy weather ensued.

In the early hours of July 25, McCain’s aircraft carriers resumed launching strikes against airfields and shipping in the Inland Sea and the Nagoya-Osaka areas. During this operation, they executed a total of 655 sorties, expending 185 tons of bombs and 1,162 rockets, successfully sinking nine ships totaling 8,000 tons and damaging another 35 vessels. The strikes also resulted in the downing of 21 Japanese planes, with an additional 61 aircraft destroyed on the ground and 68 damaged. After refueling on July 27, Halsey’s carrier forces moved to launch points located 96 nautical miles off Shikoku. At 04:43 on July 28, they resumed strikes over the Inland Sea, focusing on targets from northern Kyushu to Nagoya, as well as airfields across Honshu along the Sea of Japan. This resulted in McCain flying a total of 1,602 sorties, dropping 605 tons of bombs and expending 2,050 rockets. These attacks sank 27 ships, amounting to 43,000 tons, including the battleships Ise and Haruna, the fleet carrier Amagi, and the Combined Fleet flagship Oyodo. Additionally, 78 vessels totaling 216,000 tons were reported damaged, among them the fleet carrier Katsuragi, heavy cruiser Tone, and light cruiser Kitakami.

American pilots reported the destruction of 21 Japanese aircraft in the air and claimed 115 destroyed on the ground across 30 area airfields. They also successfully destroyed 14 locomotives, four oil cars, two roundhouses, three oil tanks, three warehouses, one hangar, and a transformer station. In support of these efforts, Task Force 37 conducted 260 sorties against the eastern Inland Sea, targeting the dockyard at Harima and sinking or severely damaging four corvettes at Maizuru. Meanwhile, the 7th Air Force’s 11th and 494th Bombardment Groups carried out a day-long raid on Kure, successfully sinking the heavy cruiser Aoba. By sunset that evening, the Imperial Japanese Navy had effectively ceased to exist, though the cost for the Americans was steep, with losses amounting to 101 planes and 88 men since July 24. As Halsey moved east to target the Osaka-Nagoya area, Shafroth’s reinforced Bombardment Group was detached on July 29 to bombard Hamamatsu. During the night, they successfully unloaded 810 16-inch shells, 265 14-inch shells, and 1,035 8-inch shells, damaging the Imperial Government Railway locomotive works, igniting a blaze at the Japanese Musical Instrument Company, and wreaking havoc on infrastructure along the critical Tokaido main line.

The following day, McCain’s carriers conducted 1,224 sorties against airfields in Osaka, Kobe, Maizuru, and Nagoya, expending 397 tons of bombs and 2,532 rockets. These strikes resulted in the sinking of 20 vessels totaling 6,000 tons and damaging another 56 ships. The pilots also claimed destruction of 115 enemy aircraft on the ground, while inflicting severe damage on numerous industrial targets, including aircraft factories and naval docks in Maizuru. In Miyazu Bay, the destroyer Hatsushino struck an air-dropped naval mine, marking the final loss of 129 Japanese destroyers sunk during the war. That night, seven destroyers advanced deep into Suruga Bay, unleashing 1,100 5-inch shells on Shimizu within seven minutes, successfully destroying or damaging 118 industrial buildings.

Typhoon weather would impede the operations of the 3rd Fleet for the next two weeks, as Admiral Nimitz ordered Halsey to steer clear of southern Japan, which was set to become the target of a new and deadly weapon: the atomic bomb. The U.S. Army had begun its project to develop an atomic bomb on August 16, 1942, under the auspices of the Manhattan Project. The project was directed by Major-General Leslie Groves and involved renowned scientists such as Robert Oppenheimer, Enrico Fermi, Niels Bohr, Richard Feynman, and Albert Einstein. Over time, it expanded to include a design center at Los Alamos and two production facilities at Hanford and Clinton.

By August 1945, the teams at Los Alamos had successfully designed, developed, and built a gun-type atomic bomb capable of forcing five pounds of uranium-235 against another 17 pounds at high speed, thereby achieving critical mass and releasing immense heat, light, blast, and radiation. The team was also experimenting with an even more powerful device: the plutonium bomb, which utilized an implosion method whereby a sphere of plutonium was compressed by conventional explosives to reach criticality. By early August, scientists had managed to produce enough nuclear material to create only one uranium device, known as Little Boy, and one plutonium bomb, referred to as Fat Man. Each weapon had the potential to annihilate an entire city, and American leaders were prepared to use them if it could compel the Japanese Empire to surrender without necessitating an invasion of Japan. A Targeting Committee led by Groves, consisting of Manhattan Project and Air Force personnel, recommended Hiroshima, Niigata, Kokura, and Nagasaki as primary targets.

Groves' Targeting Committee employed several criteria to select sites for atomic bomb targets. The chosen targets had to possess strategic value to the Japanese and be situated between Tokyo and Nagasaki. Additionally, the target needed to feature a large urban area with a minimum diameter of three miles and must be relatively untouched by previous bombings, ironically spared for potential atomic destruction at a later stage. A crucial condition was that, to the best of their knowledge, these areas should harbor no concentrations of Allied prisoners of war. However, this requirement was challenging to ascertain accurately due to a lack of reliable information about the locations of prisoners. Initially, the committee considered 17 candidates and selected five primary targets: Hiroshima, Yokohama, Kokura, Niigata, and Kyoto. On May 28, they narrowed the list to three: Kyoto, Niigata, and Hiroshima. Hiroshima was significant as it housed Hata's 2nd General Army headquarters and featured a large shipyard, while Niigata was a major industrial city with an important port. Moreover, Kyoto held considerable cultural and religious significance for the Japanese. Secretary of War Stimson, having previously cautioned General Arnold about the humanitarian consequences of targeting cities with incendiary bombings, insisted on removing Kyoto from the list after intense discussions with Groves. On July 21, President Truman concurred with Stimson during their meetings in Potsdam, deciding that Kyoto should be spared. Subsequently, Kokura, known for its large arsenal and ordnance works, replaced Kyoto. Additionally, LeMay's staff reportedly included Nagasaki as an alternate target due to potential weather issues, as it was home to Mitsubishi's arms factories, electric production facilities, ordnance works, and extensive dockyards, making it a valuable target. Meanwhile, a high-level civilian Interim Committee, under Secretary of War Henry Stimson, ultimately advised President Truman on the use of nuclear weapons, reasoning that their deployment would be no worse than the current incendiary bombing campaigns against Japan.

The committee also recommended that an atomic bomb be deployed as soon as possible, without warning, to maximize shock value and target a "war plant… surrounded by workers' houses." Following a successful operational test of the experimental plutonium bomb conducted at Trinity on July 16, President Truman authorized General Spaatz to prepare for the bomb drops before August 3. Colonel Paul Tibbets’ 509th Composite Group had been specially organized in secret since September 1944 to deliver nuclear weapons, and by June, it had arrived at Tinian under the command of LeMay’s 21st Bomber Command. General Twinning replaced LeMay as commander of the 21st on August 1, and he would ultimately issue the direct orders for Tibbets to drop the atomic bomb. The atomic bomb mission had a convoluted command structure. The Joint Chiefs of Staff were largely left out of the chain of command. LeMay was Tibbet's nominal commander; however, Groves still had extensive control over the operation through his deputy Brigadier General Thomas Farrell on Tinian. The 21st Bomber Command would determine when the atomic bomb mission was launched, based on suitable weather conditions. Even at this stage, General of the Air Force Henry "Hap" Arnold and LeMay were still skeptical about the Manhattan Project; they thought B-29 incendiary and high-explosive bombing operations would suffice to end the war soon. LeMay even questioned the 509th CG pilots' ability to conduct the mission; he wanted seasoned Pacific B-29 veteran crews to drop the nuclear cargo.

While the Imperial Japanese Army (IJA) and Imperial Japanese Navy (IJN) prepared for an impending invasion, the U.S. Army Air Forces (USAAF) continued its bombing campaign against Japan. The crews of the 509th Composite Group needed to acclimate to the navigational challenges, varied weather conditions, extensive distances, and the geography of the region, all while becoming accustomed to combat situations. Training commenced at Tinian on June 30, with conventional operational missions over Japan beginning on July 20. To prepare for their atomic missions, the crews trained with "pumpkins," which were specially constructed bombs designed to mimic the appearance and weight of nuclear weapons. This allowed them to practice handling and releasing the bombs. They also rehearsed navigational procedures, visual bomb release techniques, and dropping the weapon at an altitude of approximately 30,000 feet. Following the drop, the crew conducted high-speed, radical turns to evade the nuclear effects after detonation. During their first mission, a B-29 from the 509th sought an alternative target in Tokyo. The crew aimed to drop their 10,000-pound "pumpkin" on the Imperial Palace, but unfortunately, they missed their target. Had they succeeded in killing the emperor, it could have significantly impacted Japan's decision-making process, potentially fortifying the Japanese people's resolve to continue the war. Military leaders might have seized control in the aftermath, pushing their forces to keep fighting. Throughout their training, the units of the 21st Bomber Command intentionally avoided targeting Hiroshima, Niigata, Kokura, and Nagasaki during these practice runs. In total, Tibbets directed his crews on numerous combat missions that targeted 28 cities and involved the dropping of 49 "pumpkins." Remarkably, the 509th lost no aircraft during these operations.

While Tibbets focused on perfecting the delivery method, the weapons Little Boy and Fat Man were being transported to Tinian. Some weapon assemblies were delivered by C-54 and B-29 aircraft from Kirtland Field near Albuquerque, while the cruiser Indianapolis delivered the fissionable material for Little Boy from San Francisco on July 26. Four days later, the submarine I-58 unexpectedly attacked the Indianapolis with six torpedoes while the cruiser was en route to Guam, successfully sinking it. Of the crew, 850 Americans survived the sinking, and another 316 were belatedly rescued by August 8. By July 31, most of the assembly of Little Boy had been completed. However, a detonation expert would need to emplace the cordite charges to fire the uranium "bullet" through the gun device to the uranium core after take-off, minimizing the risk of an inadvertent nuclear explosion in the event of a B-29 crash. Additionally, the crew carrying the atomic bomb had to exercise caution when descending once Little Boy was armed because the primary radar or a backup barometric fuse could potentially trigger an explosion if the aircraft descended too rapidly with the fuses in place.

On August 2, B-29 crews arrived at Tinian with the assemblies for Fat Man. On that same day, General Twinning and President Truman approved the plan to bomb Hiroshima. Two days later, Colonel Tibbets briefed the crews about the mission, confirming that he would pilot the aircraft carrying the atomic bomb. Tibbets' B-29 No. 82, later named Enola Gay, was supported by three weather reconnaissance aircraft that reported conditions at Hiroshima, Kokura, and Nagasaki, as well as two additional B-29s assigned to conduct scientific and photographic missions. At 02:45 on August 6, Enola Gay took off from Tinian, with diversionary attacks by 604 B-29s throughout Japan also scheduled for that day, as coordinated by Twinning. After passing through Iwo Jima at approximately 05:55, Captain William Parsons and Second-Lieutenant Morris Jeppson armed the bomb at 07:30. Throughout the journey, the B-29s ascended slowly, reaching an altitude of over 30,000 feet as they crossed Shikoku and Honshu, finally reaching Hiroshima at 31,060 feet. At 09:12, Tibbets executed his final approach from the 'initial point', flying east-west over the city towards the intersection of the Ota and Motoyasu Rivers. Approximately at 09:15, Little Boy was released, and Enola Gay immediately began its turn away to escape the impending explosion. However, the bomb mistakenly descended towards the Shima Surgical Hospital rather than the intended target, the Aioi Bridge. At 09:16, Little Boy detonated at an altitude of 1,890 feet, just as Tibbets was about six miles away from the blast point.

As a result of the atomic blast, the immediate area around the epicenter was heated to an astonishing 1 million degrees Celsius, instantly incinerating or vaporizing all people, animals, buildings, and other items within that zone. Hiroshima police officials estimated that immediate casualties amounted to 71,379 individuals who were either killed or reported missing. In the surrounding areas, the blast effects crushed unreinforced structures before igniting them, resulting in an additional 68,023 wounded, with 19,691 of those injuries classified as serious. Subsequent assessments, potentially incorporating the impacts of radiation sickness or more precise accounting, recorded 30,524 individuals as seriously wounded and 48,606 as slightly wounded. Just two minutes after detonation, a growing mushroom cloud of highly radioactive dust and debris soared to a height of 20,000 feet. Within eight minutes, Tibbets' crew could observe the mushroom cloud from 390 miles away. Ultimately, the dust cloud peaked at approximately 60,000 feet in altitude. Soon after, a thick, black, radioactive rain fell upon the areas beneath the cloud. The center of the city was utterly devastated; over four square miles of the urban center, which encompassed seven square miles in total, were completely flattened, resulting in about 60% of the city’s area being destroyed. An additional 0.6 square miles suffered damage, while more than 75% of the city’s 90,000 buildings were obliterated. The ensuing fires compounded the devastation, contributing to countless deaths and injuries. Tragically, some American prisoners of war were present in Hiroshima and lost their lives in the explosion. Meanwhile, Enola Gay safely returned to Tinian at 14:58, where Tibbets was awarded the Distinguished Service Cross, while the rest of the crew received Distinguished Flying Crosses for their participation in the mission.

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Japan was broken. To be perfectly honest she had been broken long ago. Her leadership had been spending months trying to figure out the best possible way to surrender, while the civilians and troops were suffering horribly. Aerial mining strangled her of food, high explosive and incendiary bombs, killed untold scores of people, and then the Atomic weapons were let loose upon her. It was over.

- 193 - Pacific War Podcast - The Siege of Japan - July 29 - August 5, 1945

The Pacific War - week by week