Oh, no. Japan was just as broken after WWII as Germany was. There was something quintessential about Japanese culture that was broken as part of that process - their fierce belief in their own superiority. And compared to a lot of other cultures at the time, they were probably one of the closest to actually laying claim to best culture on Earth. Art and science was promoted, the poor were cared for. Life was tough, but it was doable, and you had the support of your whole country behind you. In WWII, they were swayed by the hatred of others into acting hatefully themselves, and then their fierce pride had to be utterly broken before they backed down. That's why there were two bombs dropped, when ANY other nation would have balked at one. Japan was totally "You go down at ALL costs!", and then the first one hit, and Japan just went "OMFG, but you know what, STILL NO!" It was only upon seeing the next bomb, and realizing that they truly were facing extinction, that they finally gave up. That's something that was lost to humanity and the Japanese people that will possibly never be recovered.
And as for the rest of it, let's step back to the underlying issues - the emotional and psychological basis of action that is rooted in human nature. In the matter of reason as a driving force for the species, I believe that logic and reason ARE the keys, but they are ONLY keys. As tools, they can be used for good or evil, but the difference is morality.
"There are three kinds of lies: lies, damned lies, and statistics." - Mark Twain
Morality, as I define it, is the process by which humans learn to live peaceably with each other. We are communal creatures, and tend to gather into groups for support, and as intelligent creatures have externally expressed rules for living together properly. All the oldest and most persistent rules of morality are geared towards peaceful coexistence with your fellow man. Don't kill. Don't steal - property or relationships. Courtesy and manners. All designed to allow us to live next to each other without destroying each other. All of this evolved from a purely Darwinian effort to promote the species - even wolves have a sense of society and morality. There are bits of it woven into every government and religion, though none thus far have supported a moral lifestyle completely properly thus far.
Now, often opposing morality is nationalism or group identity. It also comes from the tendency of humans to form groups for support, but what started as the purely Darwinian competition between groups for survival has evolved into the most ugly fundamental foundations of war. Us versus Them. Marking the rest of humanity as "Them" allows us to think about them as not human, and once that is done, it is a short jump to the horrors we know as war. And all this can flow most rationally and logically, once you abandon the idea of them as human beings. That is why there is always an effort to portray your opponent as a beast. The pigs. The horde. The swarm. "Them", who are so different than us. And it is also a short hop from "We cannot let them conquer us." to "We cannot let them continue to exist." And all of this can be expressed very subtly as well. It doesn't need to be as obvious as an actual declaration of war. It can be as subtle as "Gay people shouldn't be allowed to get married." Them. They aren't like us, so they must not be human. We cannot give them human rights. All prejudice and bigotry falls into this category as well.
Until humanity can overcome group identity as a justification for hatred and violence, humanity will not know true and complete peace. Until humanity knows true and complete peace, it will not be able to focus enough on their world to make the final advancements that it desperately needs to make. If our species is to survive into the coming millennia, we need to evolve past this self-destruction.















