In the near future, many envisioned a time where machines would integrate themselves increasingly into society. The lines between man and machine would blur. This division, as many expected, occurred as machines became more and more human. The eventual fear arose when they would become so human as to confuse when humanity ended and machine began. As machines evolved into becoming more human, humanity itself, could discover itself being pushed aside, first by the lack to need to exist, and finally, by force. The dystopian vision people believed would occur often ended with machines rising up to take the next step in the evolutionary ladder above us.
Thankfully, this vision proved wrong, but not in the way imagined...
The alluded line between man and machine did blur, the mixing of the two did occur. People were confused when humanity ended and machine began. However, this crossover appeared further down the spectrum than any had thought. Machines remained as inhuman, as thoughtless, as ever. They never threatened to overrun humankind nor did they ever appear to be even close to threatening our dominance of the globe. However, the irony in the future grew from the trend of humans becoming more like machines. First the onset of cyberization occurred. Then the Cyberbrain appeared, and changed the course of mankind's evolution forever.
No longer were computers simply linked; now the entire network shared one massive system. One did not own computers, just terminals to the net. Cyberbrains shared the workload. Brains became computers themselves. Humans could store their memories in their brain or in external sources and instantly recall them at any time. The answer to virtually any question sat seconds away. Now every experience we encountered in our lives would be stored digitally in our brain, downloadable and even shared... and unfortunately, open to attack, deletion, or even modification. However, one aspect of humans remained outside the realm for technology, the soul... at least, for a short time. Soon, this soul lost its spiritual definition and became something tangible, provable by science, altered by technology. They gave this a name, the Ghost, the personality of an individual. The Ghost is an aspect lost on Machines. Even in this future, machines can come as close to human as possible, but can never generate their own Ghost.
Machines have yet to emerge with their own personality. They can simulate these reactions. The definition of AI is Artificial Intelligence, recreating intelligence without really being intelligent. As the Ghost became something tangible, the technology of Cyberbrains altered. Initially, those with Cyberbrains could access anything on the net, information either from their own memory devices or from external memories like anyone could three decades before. The Shell refers to one's body, where the Ghost resides. This fact would seem obvious except that Androids soon became commonplace. They are Shells without Ghosts. In addition, those with Cyberbrains in brain boxes could exist without Shells. The term "Ghost in the Shell" was not always true.
The next question arose of what makes one human. Is it the Ghost ? So far, that appears the safest assumption, as machines cannot generate their own ghost... at least not yet. Therefore, a human being, one with full rights and privileges of being human, may not even need to have any organic parts left... or even a body. This makes ethnicity and genetic inheritance somewhat pointless... and yet, even more relevant. No one is born with prosthetics and there is a minimum age before prosthetics could be applied with any significant extent. Some have tried to remove all records of who they were before cyberization. One could change everything about themselves with perfect success, including their race or sex. However, once one's family, heritage, or ethnicity could be removed, the more important it became to keep. This kept the diversity of governments, sovereign states, and ethnic groups constant. The political upheavals occurring during this technological upswing provided a catalyst for this division between people.
In fact, a cause and effect loop occurred because of the political turmoil of the age. The onset of cyberization and prosthetics that could not only supplement the organic replacement but also improve upon it as well stemmed from a medical need arising from the side effects of not one, but two more world wars.
Just a little over 30 years ago, the planet became swept in World War III. Even though a nuclear exchange occurred, it did not regress society from a technological perspective. In fact, some of the greatest strides in science occurred during this war. Cybernetics became a fast, growing technology governments and corporations utilized to gain an edge with their adversaries.
The planet, geopolitically, changed substantially after this war. Sovereign nations altered throughout the globe. Some merged while others fractured. Paranoia, not unlike the Cold War, developed across the planet and probably led to the larger, Non Nuclear Fourth World War, which fragmented the globe even more. However, through this turmoil, one country gained dominance. It emerged from WWIII bruised but stronger willed. World War IV further strengthened its resolve to be independent and powerful. This nation was Japan...
In this future, the political game continues, more frantic than ever. The political map remains drawn in pencil. War seems on the verge of breaking out at each turn. Paranoia continues and countries fight to keep them safe. However, with the Internet totally out of one country's control, a need arose to guard the virtual borders of a country as well as its physical ones. Some of the greatest threats to a nation reside not in the barrel of a gun, but in the transmissions in the air.
Unfortunately, time is never an ally for a storywriter. Whenever a date locks down, one must come to the eventual realization that the future simply will not be arriving as fast as we would like. Kubrik envisions moon bases and missions to Jupiter by the turn of the century. Scott saw flying cars by the end of next decade. Shirow believed cybernetics would be commonplace by now.
Even though Ghost in the Shell sits a roomy 25 years in the future, time has already proven this date unreasonable for the story. Kusanagi received her first complete prosthetic body around 6 (and we know her to be in her 30s); this would mean she would be fitted with her first complete prosthetic body very soon. As we have seen, the advancement of prosthetics hasn't come close to reaching that goal. Shirow envisioned this technology catapulting due to the medical need after not one, but two more world wars. The first supposedly took place already. See where I am going with this ?
And Kahn Noonien Shing left in the Botany Bay 10 years ago. We can accept it and move on...or one could advance the clock. If one were to do that, I think 2050 would be a reachable goal. That puts WWIII in about 15 years. One can endorse this alteration or continue with the setting in 2029.