I was reminded of this while playing the new X-com game, but this theory assumes the timeline of the original games (UFO Defense and Terror from the deep), because it's been in the back of my mind for some time.
You see, the The Timeline of the X-COM games
and The timeline of the Fallout games
matches up almost perfectly. Crossover technologies (Plasma Rifles, Laser Rifles, Power Armor, biological experimentation, and even psykers) fit both series like a glove. It's almost too close to be a coincidence.
Imagine, if you will, the following composite timeline:
Sometime in the 1950's:
The time line diverges from real-world history, technology retains the 1950's aesthetic indefinitely. Real-world science takes a back stage to SCIENCE! Early conceptions of futurism, space travel, radiation, and mutation are correct.
Reports of UFO activity increase around the world. Written off by serious scientists as hoaxes, world governments have access to heavily classified reports documenting their presence as real.
Individual countries create military task forces in an attempt at direct military intervention, but these groups are unable to shoot down even a single UFO.
The UN Security Council convenes in a secret conference in Geneva. It is unanimously decided that a covert, multinational force be formed to investigate, combat, and defeat the alien threat.
The Extraterrestrial Combat Unit (X-COM) is founded, gathering the worlds finest scientists, engineers, and soldiers to deal with the alien threat. The first alien war begins.
X-COM Headquarters is founded in central California, owing to the United States status as the primary financial sponsor of the program.
The organization initially suffers massive casualties, as the alien threat employs tactics and technologies far beyond current earth capabilities.
The AER1 Laser Rifle is developed in an attempt to create weapons capable of penetrating the aliens defenses.
Slowly, X-com troopers learn to effectively combat the alien threat. After successfully shooting down UFO's and capturing their technology, X-com scientists work on reverse-engineering the enemy weapons.
Halfway through the year, an Earth adaptation of the Plasma Rifle, dubbed the Winchester P5, is successfully manufactured.
To compensate for inadequate funding from the ruling council, X-com officials begin manufacturing and selling super-advanced alien technology for sale on the worldwide grey market.
With the new influx of cash, X-com facilities expand worldwide. Bases are established in Africa, Europe, South America, and Asia. The largest of these is located in central China, and becomes a primary manufacturing hub for X-COM equipment and sales.
The X-com organization uncovers evidence of an alien base on Earth. When that base is raided, it uncovers evidence of exactly what the aliens are doing with the abductees. Experimentation with the human genetic code, cross-breeding experiments, and direct mutations of subjects.
The primary mechanism is a bizarre green goo, dubbed the 'Forced Evolutionary Virus' by X-COM personnel, its existence is classified above and beyond even the existence of X-COM itself. Officially, every stockpile is destroyed.
Late in the year, T-1 Power Armor is successfully developed based on alien technology. X-com troopers are now better protected and better armed than their alien counterparts.
X-COM scientists successfully unlock the potential of humans to use Psionic powers. The tide of the war turns in favor of earth.
Despite a now-overwhelming advantage possessed by X-COM in the micro-scale, the Aliens still possess a macro-scale advantage, outnumbering the organization by hundreds to one, with a seemingly infinite supply of UFO's, soldiers, and technology.
Alien forces increase their offensive presence, openly slaughtering civilians in the street, infiltrating human governments, and convincing them to sign non-aggression pacts. One-by-one member nations withdraw their support from the X-COM project.
X-COM agents discover the alien home base on Mars, the area called Cydonia.
A strike team is sent. The alien 'brain' which was directing the invasion of earth is destroyed, and humanity is victorious.
With that victory, a mad scramble to acquire X-COM resources ensues:
X-COM headquarters becomes the West Tec research facility, devoted to advanced weapons research.
FEV Supplies are officially destroyed. Small quantities are kept in cold storage at what is now the west Tec facility.
Knowledge of the alien threat, X-COM, and super-technology is suppressed as much as possible. Member nations fight over scientists, soldiers, supplies, and facilities. By the end of the Year, all the resources of the project are centralized in either the United States or China.
With no known way to replenish their supplies of Elerium-115, research begins on an alternative fuel source for alien technology. Plasma Rifles, Power Armor, and interstellar space craft are placed into storage until a suitable power source can be developed.
Earth's supplies of Elerium are completely exhausted.
After decades of a complete lack of alien presence, reports begin to surface of submarine alien encounters. The final dying scream of the Alien brain was a message to alien facilities on the ocean floor, signaling it's time for them to awaken from cryogenic suspension.
The X-COM organization is re-founded to investigate and deal with the oceanic alien threat. Member nations have not forgotten the aftermath of the previous war, and attempt to position themselves to receive as much alien technology as possible.
The second Alien War occurs. An element similar to Elerium, called Zrbite, is used by the aliens to power their technology, but is noted to be significantly more unstable.
Floating bases are established all across the planet, coordinating the human counter-offensive.
Eventually, the main base of the alien forces is discovered, an alien colony ship, which is now The Undersea city called T'leth, inhabited by the great sleeping god-alien who remains ever-nameless. It represents the greatest existential threat to human life ever discovered. Once it fully awakens, it will be capable of single-handedly bringing the war to an end.
On January 16, 2046, X-COM forces invade T'Leth, and kill their sleeping god. There's no need to wait for strange Aeons for death to Die, a Thermal Shok Launcher to the face does the trick.
The alien forces launch their final, vengeful counter-offensive. T'leth self-destructs, along with bases all across the planet, irreparably poisoning earth's oceans.
It is discovered that the psionic waves of the great sleeper were responsible for maintaining the stability of Zrbite. The destruction of T'leth rendered world supplies inert, and humanity must again search for an alternative source of power.
After a brief, covert, but vicious conflict over the remaining X-COM resources, the main X-COM floating base is again acquired by United States forces, and placed under the control of Poseidon Oil, a shell company for the shadow government called the Enclave.
A second divergence point. In the main X-COM time line, economic and environmental collapse prompt the world to consolidate into a single world government devoted to solving the overwhelming problems of the planet. In the Fallout time line, rising tensions between the United States and China as the two main superpowers of the planet cause a separation. The greatest minds of the age even now see that world war will be inevitable.
The Sierra Army Depot is retrofitted with technology captured from the second alien war, and becomes a dedicated research facility, testing robotic, biological, and conventional weapons systems.
A worldwide oil shortage is apparent, the United States annexes Mexico in order to ensure its domestic energy resources.
In April, the resource wars begin. Europe attempts to secure oil deposits in the Middle East, similar to America's actions in annexing Mexico, but their respective armed forces are much better matched, war drags on, bankrupting many smaller nations.
On July 27th, 2052, the United Nations is disbanded.
The “New Plague” arises in a worldwide pandemic. The source is unknown, but researchers at West tec recognize it as a derivative of the FEV strain recovered from alien bases during the First Alien War. Supplies at West Tec are taken out of cold storage in an attempt to research a cure.
In December of 2053, a terrorist nuclear weapon destroys Tel Aviv.
The United States officially sets Project Safehouse, the vault-building project, into motion.
The oil fields of the Middle East are exhausted, and the resource wars come to an end. Both sides collapse into ruin.
The fossil fuel crisis prompts China to invade Alaska. The Anchorage campaign begins.
The first crude fusion cell is unveiled, finally supplying the world with a viable alternative to Elerium-based technology. Power Armor and Plasma Rifle technology is once again made possible.
T-45d Power Armor is deployed against Chinese forces in Alaska. China rushes to create their own versions, but is decades behind American technology.
Researchers at West Tec attempting to find a cure for the New Plague with the FEV supplies experiment with its mutagenic capabilities, discovering its ability to increase the size and aggressiveness of test subjects. The military possibilities of FEV are explored.
FEV supplies are relocated to Mariposa military base.
After retaking Alaska from the Reds, American power armor units are deployed to mainland China.
In March, the President and the Enclave retreat to the former X-COM headquarters floating base on the Poseidon Oil Rig.
October 23, 2077: Bombs are launched. Who struck first is unknown, but once the first volley is fired, all other countries follow suit. In two hours, the world ends.
The Vault 13 water chip breaks down. The Vault Dweller leaves the safety and security of the Vault in order to search for a new one.