The proton bomb was a fourth-generation nuclear bomb. It had minimal radioactive emission but tremendous destructive power. In particular, when the proton bomb exploded in the water, it could destroy the sea in a radius of 5km with only 10kt of firepower. Submarines and surface combatants would not be able to survive under this tremendous pressure. Because of this destructive power, the U.S. Department of Defense classified it as a strategic nuclear weapon, not a tactical nuclear weapon, when it was used in the sea.

  The Pentagon had decided to use this MK-110 proton torpedo, which was classified as a strategic nuclear weapon. It was installed on a Virginia-class (Block IV) submarine commissioned in late 2019. In the two vertical launchers of the Virginia-class (Block IV) nuclear submarine, SLBM LGM-30F Minuteman IV ballistic missiles were equipped with six MK-110 proton torpedoes in them. This weapon had been developed to counter the Chinese Navy, which had augmented its naval military power, but now it was used against Corea, which had won the war against China.

  The United States had internal laws restricting the use of nuclear weapons when conducting a war against non-nuclear countries. However, the Department of Defense had decided to use this nuclear weapon to prevent the landing of the Corean expeditionary forces. It was because the previous ambush which cost $17.8 billion had failed. In fact, it happened because the USSC had controlled it from behind. It was then decided that strategic nuclear weapons would be used, ignoring the existing policy. The Pentagon ordered the commander of the 3rd Fleet to launch the LGM-30F Minuteman IVs.

  Shortly thereafter, the hatches of the vertical launchers were opened. The launch command code was entered from four Virginia-class (Block IV) nuclear submarines in standby. Soon, columns of water soared, and huge missiles appeared. The four LGM-30F Minuteman IV missiles spurred on the sea level, erupted in massive smoke, and soared into the sky.

  Whoosh! Whoosh! Whoosh! Whoosh!

  Four LGM-30F Minuteman IV missiles quickly broke through white clouds and disappeared from view. Although the range was 15,000km, the hit point was only 520km away. So, the four LGM-30F Minuteman IV missiles that flew at super high altitude broke through the atmosphere at a speed of Mach 35. Soon, they entered the exosphere, and the altitude continued to rise.

  The four LGM-30F Minuteman IV missiles reached the outer atmosphere in two minutes, gradually flew in an arc, and began to drop. Each LGM-30F Minuteman IV was equipped with a powerful ECM system on the missile itself. It was a state-of-the-art feature that could hinder the detection of enemy radar.

  ***

  February 20, 2021, 18:20

  CC Bunker, Yongsan-ku, Seoul (the control room of the reconnaissance satellite Apollo 2)

  Two days ago, thanks to the performance of Airman Hong Gyu-tae, the reconnaissance satellite Apollo 2 was able to detect the identity of the F-22SR Super Raptor. On this day as well, there was a lot of tension in the control room of the reconnaissance satellite Apollo 2. 36 operators focused on the screens to follow the enemy’s movement closely.

  “If anything suspicious is detected, report it immediately. Got it? You know Airman 1st Class Hong Gyu-tae of the 3rd Platoon received a reward vacation for 6 days and 5 nights and was promoted one rank, right? You guys can do it, too! Open your eyes wide and check for sure.”


  First Lieutenant Ha Tae-hyun, who was the leader of the 1st Platoon and the radar technician, encouraged the soldiers. It seemed that the soldiers were encouraged by the fact that they could immediately take a vacation after the war. They were faithful to their mission by switching various vision filters and focusing hard.

  Staff Sergeant Shin Ho-yoon, who was the highest senior in the 1st Platoon, also looked at the dedicated monitor and expanded to see if there were any parts that the computer could not find. Besides, he applied various vision filters, focusing on reconnaissance monitoring. Actually, he was supposed to be discharged a month ago. However, it was wartime. So, the period of service was extended by three months. He was thinking about becoming a professional soldier these days.

  The area assigned to Staff Sergeant Shin Ho-yoon was over Yokosuka. He was looking at the monitor while typing on the console keyboard. Suddenly, he opened his eyes wide.

  “Something doesn’t feel right.”


  On the screen, he could see something in a twisted image, flying high.

  “It might be a jack-pot!” he thought.

  Staff Sergeant Shin Ho-yoon reported about it through his headset.

  “Zone 2-21! I caught something.”


  “Really? Put it on screen No. 1!”


  “Yes, sir.”


  On screen No.1, the section that Staff Sergeant Shin Ho-yoon was assigned showed up.

  First Lieutenant Ha Tae-hyun gave an order in an excited voice. “Staff Sergeant Oh! Switch it to magnetic field mode!”


  “Yes, sir!”


  The entire screen flickered once. Then, it was switched to the magnetic field vision mode. In the air over 150km from Yokosuka Port, four hazy objects were rising into the sky. The speeds were very fast. First Lieutenant Ha Tae-hyun hurriedly approached and reported to the controller who was currently in charge of the control room on behalf of the director.

  After a while, the super-precision optical lens of the Apollo 2 was activated to capture a scene of the suspicious objects. On screen No. 3, four giant missiles approximately 8m in size and 1.5m in diameter were seen breaking through the atmosphere.

  “Communication officer! Quickly share the information with Aerospace command and Joint Chiefs Headquarters. Link the data to Zeus 1 and 2.”


  “Yes, sir!”


  “Information officer! Immediately scan the missiles and check them against the identification of friend or foe database.”


  “Yes, sir!”


  “Communication officer! Call the director as well!” Lieutenant Colonel Park Tae-gwang, who was the operation control officer, gave orders quickly but calmly.

  About a minute passed. He was starting to get impatient. He hurried the soldiers.

  “Information officer! Are you done yet?”


  “Sorry, sir. Please wait for a moment. It is currently being checked against the database.”


  “Hurry up!”


  “Yes, sir!”


  The computer could not find the data automatically. So, the information officer switched to manual mode and checked against the database one by one. He was checking all of the missiles around the world. Another minute passed. The information officer shouted.

  “I found it, sir!”


  “What is it?”


  “I will share on screen No. 3.”


  On screen No. 3, detailed data appeared along with a picture of the missile. The name of the missile was LGM-30F Minuteman IV. The operating system was SLBM, which was the latest multi-warhead type intercontinental ballistic missile operated by Virginia-class (Block IV) nuclear submarines from 2019.

  “No way…… Are they nuclear missiles?” The operation control officer who read about the details opened his eyes widely and muttered.

  At the same time, Director Na Tae-hyeun entered the situation control office.

  “Salute! Sir! Please look at screen No. 3. It seems like America has launched nuclear missiles.”


  “What?”


  ***

  February 20, 2021, 18:25

  The sea 12 km off the southern tip of Oki Island, Shimane Prefecture, Honshu, Japan

  “Sir. We received a report that four ballistic missiles, believed to be nuclear missiles, have been launched from the U.S. nuclear submarine targeting the present fleet. We are currently linking data to the escort fleet.”


  At the report of the adjutant, the captain of the fleet, Oh Seung-hwan pulled his face. He immediately picked up the phone.

  “I am informing each landing squadron and civilian ships. Ballistic missiles, believed to be nuclear missiles, have been launched to the present fleet. Therefore, from now on, we will switch to the spread formation. The 53rd amphibious group, rapidly deploy toward Oki Island! The 56th amphibious group, rapidly deploy toward the Honshu coast! Civilian ships in Groups A and B, stop the ship at the current position and wait. Civilian ships in Groups C and D! Switch to azimuth 2-1-0 and 3-3-0 respectively and maneuver faster. The rest of the civilian ships in Groups E through G! Maneuver at the current speed.”


  Even if just one or two nuclear missiles succeed to hit the area, all of the surface combatants would suffer serious damage. Accordingly, Brigadier General Oh Seung-hwan issued a spread formation order without hesitation and delivered the current development situation to the escort fleet.

  When the order from Brigadier General Oh Seung-hwan went through, the surface combatants began to turn their directions and moved. In the space above, the LGM-30F Minuteman IVs reached the exosphere, gradually lowered their altitude, and were entering a fall motion at an angle. To this end, Zeus 1 and 2, which had received data from Apollo 2, entered interception procedures.

  ***

  February 20, 2021, 18:30

  CC Bunker, Yongsan-ku, Seoul (the control room of the strategic interception satellites CS-AD Zeus 2)

  CS-AD Zeus 2 was a strategic interception satellite that entered service on February 9th. Zeus 2 control room had received data from Apollo 2. However, the precise aiming point of the interception was not captured by the powerful ECM emitted from the ballistic missiles.

  “We can’t keep lock-on, sir!” The interceptor operator shouted with an embarrassed expression. The soldiers tried to lock on to the first target, one of the LGM-30F Minuteman IV missiles, but it was repeatedly unlocked from the aiming point.

  “Zoom in 200% on screen No. 1! Operator! Concentrate and keep trying.”


  Currently, the four LGM-30F Minuteman IVs were flying toward the hitting point, drawing a parabolic line in the outer atmosphere. Soon, it would fall toward the earth, receiving the force of the kinetic energy of the falling. Not only was the detection of the ballistic missiles late, but even the interception was unexpectedly difficult. Colonel Im Su-ho, who was watching this, gave an order.

  “Operator! Just launch it as soon as it is locked on. Don’t worry about failure, just do it. Okay?”


  “Yes, sir!”


  After a while, when one of the LGM-30F Minuteman IV missiles was correctly locked at the aiming point, the interception operator immediately pulled the fire button.

  A powerful laser beam from the 50mm laser cannon flew towards the Earth. The white laser light that flew at the speed of light slightly deflected the side of the LGM-30F Minuteman IV.

  “First intercept failed!”


  “Do the second interception right away!”


  “Beginning lock-on.”


  At that time, Zeus 1 also fired a laser beam towards another LGM-30F Minuteman IV.

  Despite continued failures, Zeus 1 and 2 intercepted without ceasing and finally succeeded in intercepting two LGM-30F Minuteman IV.

  “Successfully intercepted the first target!”


  “Zeus 1 successfully intercepted target No. 3!”


  Two LGM-30F Minuteman IVs were intercepted at the engine area. Debris flew in all directions with small explosions. The missiles’ fuselages rotated irregularly. They began to burn like fireballs as they fell.

  At the success, people in the situation room of Zeus No. 2 cheered a little bit. But soon, they focused to intercept the remaining two ballistic missiles.

  The two LGM-30F Minuteman IVs, which gained the power of gravity and falling kinetic energy, fell at a tremendous speed while maintaining an angle of 70 degrees. So, as time passed, the interception became harder and harder.

  At that time, two Hocula destroyers and the Hocula cruiser Chungmugong Lee Sun-shin (CG-1101) also began the intercept operation. Six ultrahigh altitude intercept missiles, S-SSM-500S Triana antiballistic missiles, were soaring into the sky at a speed of Mach 40.

  Corean soldiers intercepted the missiles with laser beams from space and ballistic missiles from the sea. Simultaneously, a new mission was delivered to Zeus 2 from the Joint Chiefs of Staff. It was ordered to fire six C-SE Epirus (super EMP bombs) at the 3rd Fleet of the three Carrier Strike Group sailing off the shores of Yokosuka Port as soon as the intercepting mission against the ballistic missile was completed. The Joint Chiefs of Staff were launching an aggressive attack.