Schizoid Radical

An important detail about Astro Boy is that Osamu Tezuka originally had him and I believe the other robots contain electronic brains that were nuclear-powered. This was intended as an expression of Tezuka's hopes that nuclear power could be used for peace, in spite of the bombings of Japan during WWII. "Atom" is even his name in Japan for this reason, for atomic power.

"The Greatest Robot on Earth" arc has standard cartoon villain stuff. An evil king, the Sultan, who was dethroned and exiled by his people for his greed and oppression, commissions the mysterious scientist Dr. Abullah to build him a powerful fighting robot, Pluto. Pluto is ordered to take out the seven greatest robots in the world so he can prove himself the greatest, giving the Sultan his chance to rule the world. But Pluto himself is not evil and is shown to be capable of compassion and kindness even towards the robots he is tasked with defeating. He was made to fight by humans and carries out his orders.

After Pluto emerges badly damaged but victorious from his fight with Brando, he gets rescued and spared by Astro Boy, the Sultan has Dr. Abullah place a bomb inside Pluto that will have him self-destruct in the event he is defeated. Astro Boy wants to be upgraded to 1,000,000 horsepower so he can beat Pluto, something Dr. Ochanomizu disapproves of, thinking Astro cannot handle it and that it is unnecessary. After Dr. Ochanomizu is kidnapped and held hostage, the ethically questionable Dr. Tenma comes in to upgrade Astro Boy. When Astro Boy heads off towards Pluto's location, passersby who recognize him think that he has become a monster, a statement that upsets him. Astro Boy loses his first fight with Pluto, but Pluto spares him to repay the favour Astro previously gave him. Meanwhile, another masked scientist, Dr. Goji, introduces himself to the Sultan and has a robot even more powerful than Pluto called Bora. Dr. Goji is eventually revealed to be Dr. Abullah in a different guise. In the grand climax, Pluto and Astro fighting causes or coincides with a volcanic eruption that the two have to team up to control and prevent it from harming the nearby city and villages. Afterwards Pluto starts to defy the Sultan's orders to fight Astro Boy, but Bora attacks and defeats Pluto, causing Pluto to self-destruct and taking Bora out with him. Astro Boy is the only great robot left standing. In the end, Goji / Abullah reveals that he was really a robot servant of the Sultan in disguise. He wanted to help the Sultan at first but upon learning his intentions to have Pluto destroy other robots he built Bora to stop him. The robot servant vows to never build a robot like Pluto or Bora again, and takes off with the Sultan, who was sobbing over his loss and defeat. Astro Boy and Dr. Ochanomizu ponder why robots have to fight each other and hope for a future in which robots can live in peace, while visions of the great robots who were defeated appear in the sky.

The Sultan's effort to be the greatest on earth through the pursuit of power and violence was an exercise in futility. All of his efforts were in vain, it destroyed several great robots and put human lives at risk, and he even lost his own great creation Pluto. Even if you can be the strongest, there's still the possibility someone stronger like Bora may emerge, so it is only a temporary satisfaction that results in an endless anxiety to maintain that status. In the manga, even the do-gooder Astro Boy did not get an outcome he could desire by becoming a "monster" with 1,000,000 horsepower, an ability he struggled to control. Dr. Ochanomizu, the moral conscience of the story, says at separate points to Astro Boy and the Sultan that it makes no sense to compare robots by their strength. When speaking to Astro Boy, he uses an analogy to say that if the strongest people were the greatest then wrestlers would be the most important people in the world. The greatest robot in the world is then not the strongest, but the one who is intelligent, does what is right, and works with others towards peace. It is a simple moral story for children, a commentary on global politics, and a sci-fi tragedy all rolled into one.

Although a lot of the story is changed for Pluto, Naoki Urasawa remains faithful to Tezuka's message and expands upon it. Tezuka wrote the Greatest Robot on Earth during the Cold War, when the Vietnam / Indochina war had been underway and was heading for its highest point. Urasawa wrote in a different time, but incorporates clear analogies to the Iraq war and the war on terror. The seven great robots are directly called "weapons (or robots capable) of mass destruction." Production of these robots became restricted by an international treaty advocated by the United States of Thracia, a country that is not part of the world's version of an international criminal court. After the treaty was enacted, the Kingdom of Persia was accused by Thracia of producing a robot capable of mass destruction under the mysterious Bora project. The Bora Survey Group was sent in to investigate the allegations. While it could not verify the allegations, the Survey Group did uncover a dispensary of destroyed and disposed robots, analogous to a mass grave. After the Bora Survey Group withdrew from the Kingdom of Persia, United States of Thracia led a multinational force invading the Kingdom of Persia, changing its regime to a democracy. After Darius XIV falls, the peacekeeping forces arrive and become as occupiers. Both the invading forces and peacekeepers include these robots of mass destruction (all seven great robots), so it is seen as the strong nations picking on the weak. Near the the cusp of defeat, Darius XIV and Abullah plot to get revenge by eliminating the strongest robots, members of the Bora Survey Group and against Thracia. The Bora project, which initially started as an effort to make Persia's dry deserts flourish, is now used for something more sinister now that its director has become consumed by hatred and the desire for revenge.

There are additional clues to the nuclear analogy too. Most obvious is Epsilon's photon energy, which is capable of turning people and robots to ashes, but is also being researched for peaceful purposes. The seven great robots are viewed as keeping the world in balance, like some kind of nuclear equilibrium of mutually assured destruction. The United States of Thracia does not possess one of these, unlike the real USA which has the largest arsenal of nuclear weapons in the world. Elimination of the seven great robots is seen as altering the balance of world power. In the background, Thracia is revealed to have a highly intelligent supercomputer, personified by the teddy bear Roosevelt, that has been calculating behind the scenes. Thracia's president, who is given partial information, believes that the robots being eliminated will be Thracia's opportunity to become a great and powerful nation. It seems this may have been the intention of both the 39th Central Asian war as well as the international treaty forbidding new robots of mass destruction. What the President is not told is that there is still Bora, who is capable of setting off a bomb that can destroy most human life on earth. While the President is assured survival, it is on the condition that he becomes a slave to the supercomputer Roosevelt. Like the Sultan in Tezuka's story, his pursuit for greatness by means of power and warfare failed, and made him become entrapped in an inescapable and lethal struggle.