The atomic bombing of Baku did not impact the Soviet union alone. By late July 1945, nearly 95% of Japan's oil production was being provided at the expense of the Soviet people. While the IJA had touted their railway from Indochina to Manchuria as a lifeline that would sustain the empire indefinitely, in reality the route only provided a fraction what Japan needed under ideal cicumstances, which Chinese partisans and American bombers made sure never occured. Still, it was no surprise to Prime Minister Yonai that Stalin gave no notice that their fuel trade was cancelled, nor that they also repossessed any Japanese oil still on Soviet railcars.
Before the second phase of the war even broke out however, Yonai had been planning an operation to knock out the American bomber bases once and for all. In mid May, the IJN's fleet of cruiser submarines was tasked with a critical mission, the delivery of aviation fuel to the Phillipines. Japan had eight of the largest submarines in world (plus another dozen smaller cruiser subs) the I-400 class submarine. The boats had the range to circle the world, as well as a three plane aircraft hanger for floatplanes. However, no floatplanes would be carried for this mission (nor any torpedoes or deck gun shells) instead, every nook and cranny of the vessels was stuffed with barrels of fuel, and the crew reduced to the bare minimum to save space. While only three older subs were sunk despite all of them making multiple trips, many crew members were poisoned by the fumes in the sometimes leaky barrels.
More difficult was the transportation of the aircraft themselves. While there were generally more experienced bomber pilots than fighter pilots, they were still in the minority. Furthermore Japan by this point was more or less aware that their codes were broken, and so to conceal the scale of the operation, delivered most orders via messenger plane. The result was that despite moving nearly 900 aircraft from the Japanese Home Islands to The Phillipines, US inteligence merely reported "Aware, minor air assets transferred to Phillipines.
Yonai had personally ordered War Minister Itagaki (with himself speaking as Navy Minister) to cooperate across the interservice rivalry when planning this attack, ensuring equal commitment on both sides. Saburō Sakai volunteered to lead the naval aircraft, but was denied as his death would be a blow to morale, and the naval strike was instead led by Tetsuzō Iwamoto. The Army aircraft would be led by Satoro Anabuki, who was granted an audience with The Emperor before departing. Because of the communication blackout, General Yamashita was caught off guard by the number of planes arriving.
Indeed the Japanese position in the Phillipines was beginning to deterioriate. While the Fillipino guerillas had only killed about 12,000 Japanese so far, disease and other causes had killed twice as many, a tenth of Yamashit's garrison. While the men could be fed by the local agriculture, other supplies including ammunition and medicine had to be shipped in, and so none had arrived in almost a year. The only ships now were moving between ln the islands, where American submarines rarely hunted, though even they were being done in by lack of fuel or coal. The island was also occasionally bombed from the Marianas, her planes almost grounded by fuel and pilot shortages
As such many crews found themselves in a tense environment, rookie pilots surrounded by war weary isloated veterans. The aircraft were an even mix of army and navy planes as promised, most of them newer models. About 200 fighters, 400 light bombers, and 300 twin engined bombers, including sixty G4M's carrying Okha's. The light aircraft didn't have the range to return to the Phillipines for the most part, so their crews were given limted choices. They could either crash their aircraft into the runways, parachute out and join the resistance on the islands, parachute on an isolated Japanese occupied island, or fly anywhere and take your chances with the sea, all at the pilot discretion.
The first strike took off in the wee hours of August 6th, 1945, the Americans still none the wiser. Indeed despite prior attacks by air and sea, air defenses were once again reletively slack. 600 fighters including 150 nightf fighters guarded the entire chain, but only a fraction were in the air at any time. At the very least these planes were modern, many of the new Bearcat fighterss had been stationed here as sort of combat trial. Additionally, 200 more night fighters were provided by several escort carriers in picket stations around the islands.
The attack was split into two waves, the first consisted of most of the fighters and light bombers, intended to come in hot and draw fighter fire, while the second wave would arrive later and bomb from high altitude. The attack was spotted 200 miles out by picket destroyers, but the night fighters were scattered and hampered by the dark moonless sky. Arriving just as dawn broke over the islands, the Japanese attack began. As Guam and Tinian each had three and Saipan only one airfield, they took priority. The fighter garrison scambled, and in newer planes, the better pilots triumphed against the Japanese.
Still, many planes made it through, even those critically damaged. Some carried incediaries, some carried modified anti-air rockets, nicknamed "Fireworks" by the Americans. As the attacks came, many bombers were destroyed on the ground, their crews not daring to try and fly them off in all the chaos. Few pilots decided to ditch, some of the last planes fired all their ammo before diving into the runways. One remarkable feat occured during this attack. WASP pilot Jean Landis, who was flying a Bearcat into Guam, became the first American woman to score a fighter kill (and assisted another). The fighters took 28 aircraft destroyed, as well as 60 damaged. But almost as soon as the first wave was over, word came in that more planes were an hour out. Despite having fuel to intercept, many fighters had to return to base to reload.
As around 240 scattered Americans apporached the bomber formation, they at first achived results. The unarmored underarmed planes were torn up, but many of the again peeled off due to running short on ammo. These heavier bombers carried various armaments, many had bombs designed to crater the runways themselves, to delay the landing of replacements. Notably, all 60 Betty's dropped their Okha's unmolested, and all of them returned, save three for mechanical issues. Many still were intercepted, but the bombs still wrought havoc. While only 134 aircraft returned to the Phillipines, they managed to destroy 203 and damage nearly 300 B-29s, along with damage to infrastructure that took two weeks to repair. It was the single largest disruption to the bombing of Japan of the war, but it only lasted three weeks. A surplus of aircraft produced was waiting, and losses were made good quickly. Yet it still meant that for three weeks only two raids struck Japan, a victory for many.
Anabuki himself got incredibly lucky. He'd managed to escape the dogfight intact and fly West, nursing his fuel starved aircraft within 200 miles of the Phillipine coast before ditching. The winds were in his favor, and two weeks later he washed up on Samar, one of only six ditched pilots to be saved. Still, many valuable planes and pilots were lost, which some would argue were better spent protecting Japan directly.