The offensive was of a scale unseen since Operation Lucifer in 1999. The Imperial Navy and Army deployed the Second and Third Fleets (a mix of battleships, cruisers, landing craft, submarine tenders and the TSFs from the Imperial Army, as well as other land forces). The UN added their 6th Orbital Diver Corps and HSST transport fleet, the UN's Pacific Fleet, ammunition counts totalling half of the Far East Defence Line's munitions store, Special Task Force A-01, the XG-70b Susanoo II, piloted by the 00 Unit, and Professor Kouzuki Yuuko stationed on the Mogami, acting as the executive officer of A-01's side of the operation.
The battle would go down in history as humanity's first step towards triumph against the BETA, and is regarded by many Japanese military personnel to be the turning point in the war, one way or another.
In the Unlimited/Day After timeline, the success of Operation Iceberg was achieved through the use of G-Bombs and was considered to be the final test of the strategy to be used against each Hive in Operation Babylon.
At 08:56 hours, the Imperial Navy's Second Fleet, led by the Shinano and comprised of the warships Mino, Kaga, several other Yamato-class battleships, Mogami-class cruisers, Type-81 submarines led by the Takashi, and a force of Osumi-class assault ships led by the Takao, approached Sadogashima from its south-west, towards Mano Bay. Imperial Navy shelling of the Kawada coastline was timed with the arrival of orbital bombardment munitions dropped by the United Nations' HSST fleet, with the total aim being to reduce and neutralize the anti-air capabilities of any on-site Laser-class BETA.The A-6Js of the 17th Tactical Armored Unit, of the Imperial Navy Marine Corps, launched next, attempting to make landfall. The Second Fleet, having cleared the coastline of Old Yawata Town, moved their shelling onto the abandoned town itself, even as the 17th Unit's Stingray Squadron made landfall on the shores of Mano Bay and began their assault.
With a foothold secured, the Imperial Army's Whiskey Unit began their assault from the west side of the island. The assault ships braved a storm of laser fire from the BETA to get their pilots into the fray and support Stingray Squadron, and the Imperial Army began to pull its weight in combat as the BETA were pushed back from the shoreline. Moments later, the Second Fleet fired upon coordinates provided by Stingray in order to neutralize Laser-class BETA, further adding to enemy casualties.
The Valkyries' ArrivalEdit
1 hour and 13 minutes into the battle, the bombardment continued with Old Yawata and Kawada Towns secured by Whiskey Unit. With the assault now on stable footing, Echo Unit, a task force approaching from the north-east towards Ryoutsu Bay, began landing troops on Sadogashima. At this point of the battle, the Imperial Navy had lost up to 81 naval craft, with 49 of those being Osumi-class assault ships and another 52 ships damaged.
Whiskey Unit was split into different groups; Whiskey Alpha was called to advance into Old Takatsuka towards the Hive, while other battalions held their position; some were ordered to face down a sudden division-sized BETA reinforcement unit that had emerged from the Hive, and others were to infiltrate the Hive from other gates.With Echo Unit reaching Ryotsu Bay, the Imperial Navy's Third Fleet, led by the Yamato, began their bombardment as well. Under the cover of naval artillery, Echo Unit scrambled their remaining TSFs, with Special Task Force A-01 amongst them; the 00 Unit and the Susanoo II, however, were held back at the mainland. The Imperial Army deployed mostly around the north and middle of Sadogashima, while STF A-01 forced their way inland from the east of the Hive, fighting through waves of Destroyer- and Grappler-class BETA to clear the way for the Imperial Army's 4th Squadron alongside them to reach Old Kaminibo. The UN's 6th Orbital Diver Corps then made landfall at the west of the island, burying the BETA underneath them in a hail of metal fragments as far as the Valkyries' position. Their descent deposited many of the Divers directly into the outer tunnels, Henri Gischen and the Aquila Squadron included, and allowed them to proceed into the Hive relatively undisturbed.
CounterattackEdit3 hours and 47 minutes after the operation began, the Orbital Divers had infiltrated up to 440 meters into the Hive. Despite sketchy communication lines, the Orbital Divers were doing well; Sauber Squadron, leading Ghost and Lezard Squadrons, had penetrated into Hall N19 of the Hive's many side tunnels in their goal to reach the Hive's main shaft, with Whiskey Unit's Lima Battalion close behind at Hall M15; Juliet and Kilo Battalions brought up the rear, cleaning up BETA left in the 10th stratum of the Hive so as to secure supply lines. Mike and November Battalions had also began their own infiltration operations from other directions, and other units on the surface continued to fight with minimal losses.
Sauber, Ghost, and Lezard Squadrons were caught off-guard when a massive wave of BETA reinforcements reached their position via tunneling upwards (mimicking an "elevator") from the 13th stratum. This caught the Divers by surprise, as no BETA have ever been recorded to create new and uncharted Hive Shafts in such a short time. The BETA quickly broke the Divers' data link to their command post, preventing word from getting out about the 40, 000-strong BETA reinforcements to their surface comrades. The Orbital Divers were soon overrun, followed by the loss of Juliet and Kilo Battalions. Mike and November Battalions were forced to abandon their plans of infiltrating the Hive, and retreated back to the surface.
Even as the tide of battle turned for the worse inside the Hive, Echo Unit, STF A-01, and remaining Imperial Army forces continued fighting the BETA on the surface. With 40, 000 BETA and more emerging from every possible Hive Gate to the surface, a decision was quickly made to bring in A-02, the Susanoo II.
Captain Isumi Michiru of STF A-01 then split her unit into three flights; A Flight would be led by Captain Isumi, with 2nd Lieutenants Sakaki Chizuru, Yoroi Mikoto and Tamase Miki following her lead. Platoon B would be under Hayase Mitsuki, with 2nd Lieutenants Shirogane Takeru, Mitsurugi Meiya and Ayamine Kei under her command. Lieutenant Munakata Misae would lead Platoon C, comprised of Lieutenant Kazama Touko, and 2nd Lieutenants Suzumiya Akane and Kashiwagi Haruko.Without warning, the BETA switched tactics, with a significant numder of them in the immediate area aiming for STF A-01. Captain Isumi quickly requested for artillery support, and ordered the squadron to bring as many supply containers as they could with them; a defensive position at the dried-up ruins of the Nibo Dam 2, 000 meters ahead of the Susanoo II's attack point was set up so as to head off the BETA. The artillery proved ineffective, with the BETA of the Sadogashima Hive having hidden many of their Laser-class BETA underground in the initial assault to prevent the bombardment from killing them and only bringing them out at this moment. A decision was made to change the Third Fleet's munitions to anti-laser shells to provide a diversion for the Laser-class BETA, to protect STF A-01 and the Imperial Army TSFs from being shot at. Professor Kozuki, however, suspected that the BETA might have been holding back its Laser-class/Heavy Laser-class BETA to wait for the Susanoo II to make its appearance.
Despite nagging insecurities, the plan was carried out, with STF A-01 arriving ahead of time at Nibo Dam. A and C Platoons shut down their TSFs behind cover and waited for the BETA, especially the faster Destroyer-class, to pass their ambush point, while B Platoon did the same at the end of the ambush zone; once the last Destroyer-class crossed the ambush line, A and C Platoons then fired upon the BETA, and once the Second Fleet began laying down heavy metal clouds as cover, B Platoon turned and joined C Platoon in hunting down the Laser-class BETA, with A Platoon destroying the remainder of the Destroyer-class.
Taking heavy losses, the remaining BETA closed their formation around the remaining Laser-class BETA, using several Fort-class to harass STF A-01. Urged by a need to clear the field of laser fire to prevent the Susanoo II from being shot down by concentrated blasts, 2nd Lieutenant Shirogane engaged the BETA, using himself as bait to draw the BETA screen away. Overcoming massive numbers and killing twenty Fort-class BETA in the process, Takeru managed to lure the majority of the BETA away, allowing the rest of STF A-01 to charge in and eliminate the Laser-class BETA.
Even as STF A-01 worked their plan east of the Hive, Whiskey Unit's Cracker Platoon was engaged with the BETA at the Takase-Sawane Defense Line, south-west of the Hive. With artillery support taken up everywhere, their positions were quickly overran, and only the timely arrival of the Royal Guards' 16th Guard Battalion, with the 19th Independent Guard Flight under them, and led by Ikaruga Takatsugu, saved 2nd Lieutenant Isumi Akira, the last platoon member, from following her teammates. The 16th Guard Battalion then plunged into the fray, killing as many BETA as they could. The Imperial Navy themselves were in no better shape; the fleet's ammunition reserves were less than 20%, with Whiskey Unit losses at 55% and Echo Unit losses at 37%, with their main force pushed to the northern tip of Sadogashima.On the north-eastern front, STF A-01 continued their assault against the BETA, only leaving the area when notified that the Susanoo II was about to begin its attack run. Despite simultaneous strikes by eight Heavy Laser-class BETA that were not cleared from the area in time, the Susanoo II withstood the blasts and more, shocking all on the field. Its next act silenced all doubts about its capabilities; a single blast from its Charged Particle Cannon cleared away almost the entire Hive monument, as well as nearly all the BETA on the surface. A second blast from the Susanoo II was fired later, this time sweeping away the remainder of the Hive monument. With the area cleared in mere seconds, STF A-01 gathered their supplies and wits and prepared for the next phase; for the 00 Unit to link with the Hive Reactor.
Despite its immense firepower, the Susanoo II lost all functionality soon after, crashing to the ground. Refusing to let this chance die, the Imperial Navy and UN fleets renewed their assault on the remaining BETA even as Laser-class BETA fired back. The Second Fleet took the most severe hits in this exchange, with several ships suffering heavy damage; even the Shinano did not escape unscathed, although the fleet remained in fighting condition by overusing anti-laser countermeasures. Reduced to data-link sighting with other units on the island, the Second Fleet continued to provide support fire even as STF A-01 scrambled to evacuate the 00 Unit from the downed Susanoo II, which had resisted all attempts to restart itself and was being swarmed by Tank-class BETA.
When all hope to restart the Susanoo II was lost, Captain Isumi was given the task activate the Susanoo II's self-destruct, while 2nd Lieutenant Mitsurugi was tasked to retrieve the 00 Unit and fly west in NOE flight to avoid getting caught in the tsunami that the Susanoo II's explosion would produce. Even as assault ships were quickly redeployed to retrieve remaining Whiskey and Echo units, STF A-01 quickly formed around the Susanoo II. 2nd Lieutenant Shirogane set his TSF to a remote-control link with 2nd Lieutenant Mitsurugi's unit, while Captain Isumi set her's to 2nd Lieutenant Kashiwagi, and the two entered the interior of the Susanoo II.
Despite the shock of seeing what the 00 Unit really was, both Captain Isumi and 2nd Lieutenant Shirogane were quickly occupied by a renewed attack by a division-sized BETA herd. While STF A-01 moved further out to intercept, Yuuko and Imperial command worked to find a way which to safely evacuate the 00 Unit; the sudden appearance of Heavy Laser- and Fort-class BETA at Mano Bay sealed off the 00 Unit's original eavcuation route. Imperial Command then decided to kill two birds with one stone; instead of waiting for resupply and wasting time, they would have the Second Fleet charge into the range of the BETA with the last of their reserves. This would buy time for STF A-01 to evacuate the area, and would also allow Whiskey Unit to retreat from the battlezone under allied cover fire.
A team comprised of 2nd Lieutenants Kashiwagi, Mitsurugi, and Shirogane, were formed to transport the 00 Unit through the escape route, but their paths were blocked by a formation of BETA. Unable to circumvent them in time, they decided to charge through, but found themselves slowly outnumbered, with Kashiwagi's unit taking enough damage to impede her escape. Opting to return to Captain Isumi's instead, the team proceeded, with Lieutenant Mitsuki and 2nd Lieutenant Tamase coming to their aid later on. Even as the other members of STF A-01 fought their way through the enemy blockade, more BETA moved to obstruct the 00 Unit's escape path, and the Second Fleet continued to take fire from the remaining Laser-class BETA, refusing retreat in order to cover the remaining members of Whiskey Unit.Within the Susanoo II, program errors prevented Captain Isumi from activating the autopilot of the Susanoo II, and Professor Kouzuki ordered her to settle with getting the self-destruct up and running. However, the sudden appearance of fresh BETA forces underneath the Susanoo II, which were also headed towards the mainland, forced Professor Kouzuki to order Captain Isumi to evacuate, and for the ships of Echo Unit to bombard the Susanoo II.
As the rest of STF A-01 retreated, 2nd Lieutenant Kashiwagi, who was in Captain Isumi's unit holding off the BETA with her own machine on automated control, was overwhelmed in combat and killed. Foreseeing no other escape, Captain Isumi stayed back to activate the self-destruct function of the Susanoo II, and with her final words to Professor Kouzuki and STF A-01, the Moorcock-Letche engine went critical, swallowing the entire island and wiping Sadogashima off the map.
AftermathEditAlthough a tactically sound victory, the aftertaste of Operation 21st left many with bitter feelings; the loss of the entire island meant that not only were any potential survivors confirmed dead, but the coverup of the explosion as a G-Bombing caused many to feel resentment towards having to rely on US technology to once again win a battle. The tsunami caused by the explosion devastated Japan's western coastline, causing loss of assets and early-warning systems.
Apart from the loss of two of STF A-01's members, other casualties include Henri Gischen and Aquila Squadron, the remainder of the 6th Orbital Diver Corps, and those of Whiskey and Echo Units who had been lost in the initial combat, and others who could not evacuate in time. The loss of the Susanoo II was also a great blow, although its effect would not be as great as many thought it would be.
Despite the victory, Operation 21st would immediately lead into the Defence of Yokohama Base, a disaster of even greater magnitude than the sudden breakdown of the Susanoo II during this operation.
In the Windows 7 edition of Alternative, Shirogane Takeru becomes a celebrity within the Yokohoma Base following his exploits during the Battle of Sadogashima. Shirogane is surprised at this, since the Special Task Force was deployed in secret. He learned of this development from the guard posts, the same ones who apprehended him during Unlimited, who referred to him as "Shirogane-dono". This subject only comes up once and isn't referenced to afterwards.