Turtledove's "Road not Taken" in 1945.
In this world, another bunch of pre-scientific aliens descended upon British India in October, 1945, with plunder and conquest in mind, only to run into machine guns, anti-aircraft artillery, overlapping fields of fire, etc. The dark red, somewhat slimy and rather appendage-gifted Ssslethy being rather less cute than the teddy-bearish Roxolani, and the Indian Army of 1945 being a trifle more ruthless than the US army of 2039, none of the invaders survived: however, the antigravity generator for one of their shuttles was captured intact.
Earth scientists have spent the last 65 years banging their heads against the incontrovertible fact that if you arrange copper, quartz crystals, and a piece of magnetite in a certain configuration, and rotate it, you get an antigravity field, in spite of there being no discernable reason why this should be so. Quantum mechanics has gone off in some very odd directions, most of them dead ends, since 1945, as have theories of gravity, mass, etc. (Nobody is building a quantum computer anytime soon in this world, for one thing, and there's no equivalent of string theory: the laser wasn't invented until 1974 due to research going off in other directions). Some new theories about the structure of space-time seem to offer some hope for an explanation, but since they also seem to indicate that General Relativity is full of holes and there really is no such thing as Dark Matter, the general response from the scientific community has been skeptical.
A sizeable contingent of the London government, headed by Winston Churchill, pushed for keeping anti-gravity a British secret, for the establishment of a new British Empire In! Space!, but given the economic condition of the UK at the time, pissing off the Americans was in the end too much to risk. (Also, the secret probably could not have been kept long from the US, given the extreme simplicity of the basic mechanism: it only took eighteen months for the Soviets to steal it, after all).
The Cold War became frigid even faster than OTL, given the antigravity technology gave the Soviets the capacity to easily transport nuclear weapons to the US right from the start of their production. It also made large-scale invasion of the US heartland a relative snap: it after all only took a few horses on treadmills to whirl an anti-gravity generator powerful enough to put a battleship in orbit. By 1955, skies over the US and the USSR swarmed with huge flying fortresses ready to repel invaders.
An outlet for human energies was fortunately found in space. A B-17E Flying Fortress hastily refitted for vacuum conditions reached the Moon in 1946, and it would not be long before the planets were reached. However, it was not until 1953 that the crew of a US "space torpedo" (early purpose-made US spaceships tended towards the "heavily armored spindle" design) experimenting with the various geometries of the antigravity field discovered that it could take on more than three-dimensional forms: the story of how, after some very desperate weeks, they managed to navigate their way back to Earth from interstellar space has made for a multitude of books, movies, and TV specials.
The Cold War never so much ended as eventually faded into unimportance as both sides found themselves with far too much to chew beyond the sky: the unfortunate General Ripper incident might have brought apocalypse, but the damage was kept to the destruction of Omsk and Columbus, Ohio, and brought about a vigorous mutual disarmament program. Currently the inner solar system is a nuke-free zone.
In 2010, as a result of the 1978 Treaty of Shanghai, space beyond the 100 light year line is divided up into six sectors, extending outwards to infinity across the arm of the galactic spiral. These sectors mark the "sphere of expansion" of the five Earth Blocks, which in a Treaty of Tordesillas-type arrangement have essentially divided up all of outer space between them. The US-British Commonwealth block, the Soviet Block, the European-Japanese Block, the Chinese Block, and the fractious Third World Block (headed by India) each have their own sectors, while the sixth is the International Sector, supposedly run by the UN, but in effect a scene of constant political maneuver and claim-jumping by the five Blocks. Within the 100 light year line are the First Expansion worlds, colonized in the first wild, chaotic two decades of the Interstellar era.
Besides off-world considerations, there is a common problem which accelerated the end of Cold War nuke-wagging: the perpetual Meteorist problem. The Meteorist is a person which for ideological, religious, or personal nuttiness reasons turns him or herself into a living meteor, obtaining or stealing control of anti-gravity flyer and turning it into a kinetic weapon. Even in the atmosphere, an anti-gravity drive ship can move a lot faster – and therefore impact a lot harder – than any chemically fueled ships, and if they have a deep-space start and a thick enough hull to avoid incineration in the upper atmosphere…well.
Although all pilots are now carefully vetted, control rooms guarded, deep space ships built to burn up if they hit the atmosphere fast and within-atmosphere fliers designed to be sufficiently un-aerodynamic to break up much above the speed of sound, the anti-gravity drive is too easy to build to keep out of irresponsible hands: if alien peoples who haven't figured out bronze yet can build spaceships, so can the most screwed up of third-world nations: so can any terrorist group with access to some skilled builders and engineers (and engineers are usually well represented in terrorist organizations). All the major nations have been forced to cooperate closely to maintain the formidable international network of INTERPOL-AG, the Antigravity Crimes and Terrorism unit, which almost every week busts some new group building unlicensed ships: "rogue" nations after their own colonies, wealthy egotists, terrorists, madmen, and some guy trying to get away from his wife. And in case someone slips by them, there are now extensive batteries of AG-powered interceptor missiles set up on Earth and major colonies: still, ever now and then Lady Luck rolls snake-eyes, and several times already a large part of some city or other has risen into the sky in fragments.
One of those was Tel Aviv, 1993, and the Israelis finally gave up, packed it in, and headed out for Judah, a planet 612 light-years hubwards in US-British space where a great many Jews had already moved. The Arabs are _very_ annoyed that the Israelis, with a massive effort, not only took all their worldly goods with them, but also took their houses, the historical monuments, the plumbing, the olive trees, a number of archeological sites with up to 30 feet of soil, and the entire Temple Mount. (Although they did drop off the Dome of the Rock in Jordan).
Although the Meteorist Menace remains a worry, life is generally better than OTL for most people on Earth. Anti-gravity has brought cheap power to the world (unlike many SF writers, engineers have been transforming linear motion into circular motion for rather a while), and although regulation of airlines is tight, travel by anti-gravity flyer is a good deal cheaper and generally safer than airplane travel OTL (not that plane travel is particularly dangerous, and no, Pan-American is paying me nothing to say this. ) Anti-gravity and FTL make bringing raw materials – even foodstuffs – across space profitable, and raw material shortages are pushed into the indefinite future. Overpopulated nations can ship their poor to the colonies.
Due to the whole "stuff plummeting from the sky" issue, the flying car is not to be found on Earth, although it is allowed in a number of space colonies. There are a number of floating buildings and even some floating cities, and some very odd pieces of mobile, floating sculpture. The night sky is full of the drifting stars of space settlements, factories, resorts, etc.
Far superior transportation means there are even fewer isolated spots on this world than on ours. The speed and cheapness of air-near space travel and materials transport means that New Zealand is almost as economically integrated with the US as Canada, and nowhere on earth is more than a few hours away from anywhere else. The fact that an anti-gravity flyer laughs and points at aerodynamics (and can always rise above the atmosphere to get out of the weather) means that everyone has been to the top of Mount Everest (there's a coffee shop up there now, the same as there is a hotel at the South Pole). The hotel at the South Pole offers "the best cross-country skiing in the world". Taking a flier to the top of Mount Everest and walking down is a popular hike. Communications satellites are cheap, so everyone has a satellite communications hookup.
Illegal immigration authorities now have to deal with people sneaking across deserts and stretches of open ocean with wee little crappy anti-gravity fliers (stalling speed is another problem antigravity fliers don't have to deal with, so you can fly low and slow): although possession of an AG generator allows you to detect other ones, the FTL signal makes it rather hard to pick out a weak little source from all the other anti-gravity fliers going back and forth within a few hundred miles. The Pacific Isles have become rather depopulated by people bored with their tourist-infested life style, heading off in crappy home-made flyers for the lands of Actual Careers, or in the case of some daring traditionalists, headed off to the stars in barely air-tight craft (some may have even survived). There is Navel-of-the-Sky, but it is under UN administration and the traditional-minded fear the exchange of one nanny state for another will do little to restore the traditional values.
Global food production is higher than OTL, thanks to the introduction of a number of edible alien plants that thrive in conditions that would defeat all but the toughest Earth weeds. (On the downside, some have escaped from farms and become nuisance plants in the wild. The nasty possibilities of alien animals doing the same has led to strict laws against their importation, which failed to prevent the Hurkle from becoming a real pest throughout much of the western hemisphere). Curious alien artifacts from many worlds do a brisk trade, although due to the backwardness of alien technology there is little in the way of mass-produced imports. Global warming, with antigrav power replacing coal and most oil, is much less of a problem.
Military logistics are greatly eased by anti-gravity transport, which has helped lengthen the life of the Soviet Empire and also helped keep colonial empires going a bit longer until international disapproval and the greater opportunities of space (plus the fact most colonies on earth were a financial sinkhole) brought them to an end. The French managed to do well enough in Vietnam to declare victory and pull out (although the right-wing "loyalist" government they left behind was overthrown in a decade) and even today Europeans still run a number of little dibs and dabs of territory here and there which they abandoned OTL but remain connected to the Metropole by antigrav fliers, which can always just drop straight down from space if surrounding territory is hostile. OTOH, strong-arm tactics in the third world have become less frequent since it became a possibility for, say, Indian fliers to arrive and drop off a bunch of troops with tanks within an hour.
Although some fields of technological endeavor benefitted in various ways (the telescopes on the far side of the Moon are huge), generally the scientific/technological state of the art is a bit behind OTL, due to the massive resources put into technology related to space colonization. Biotech is a bit more advanced than OTL, due to dealing with alien biochemistries and ecologies: computer hardware is slower, and the internet relatively rudimentary.
THE SETTLER COLONIES
A great many colonies large and small have been created by the Five Blocks. (Lesser un-aligned nations settle planets with UN or Block permission, or else). Most of these are outside the solar system: if there are green worlds with breathable air hardly further away by FTL, why go to the trouble of settling lifeless (save for some deep-rock Bacteria) Mars? And livable worlds are common enough that ships provisioned with the alien equivalents of hardtack and salt beef, and the ecological cycle maintained by a bunch of potted plants, still managed to find them before being forced to turn back.
Of course, there were exceptions: a fair percentage have biologies too alien or ferocious to sustain Earth-life even with imported plants and animals, but by 2010 there were over 300 extra-solar planets with over 1000 Earth inhabitants, for a total of (very roughly) 117 million humans living in the realms beyond Pluto. The planets claimed in the frantic First Expansion, when all the major nations were busy "planting the flag", tend to be closer together in space and crappier to live on than the post-Shanghai colonies. Some, such as Frostbite, have largely been abandoned. Although some of the new worlds are mostly important for their mines, not being particularly pleasant places to live and raise crops, many of them have been specifically chosen for their suitability for human habitation, and although there have been a few oopsies (the parasitic fungi on Ten Thousand Islands, the Incendiary Trees on New Washington and their rather destructive life-cycle), great numbers of humans now raise hay on planets green and pink and purple, busily slaughtering the local life, burning down the forests, strip-mining the hills and other such fun activities now complained about by busy-bodies back on Earth.
Of late, there has been an increased interest in lifeless world settlement, on asteroids and so on: it is after all a niche for which there is no alien competition, and although zero-gee conditions are still a problem, the ability to put huge masses in space means that people _can_ build big-ass type O'Neil colonies to rotate, and with walls thick enough to block out that pesky radiation. It's still cheaper to settle oxygen planets, but the "The Vacuum is ours" boosters have become a political presence.
The UN-administered International Sector is where anybody, from any nation, Block member or not, can set up a colony under UN overall authority. Many of the cases of dreadful colonial Fail have taken place here, such as the Albanian effort, the Iranian effort, and the Moonie effort. Various eccentric individuals have set up camp on barely-habitable worlds and claimed the role of Planetary Monarch with nobody but the purple one-eyed rabbits to dispute them. There are also some sizeable national colonization projects, notably the Islamic worlds of Ataturk and New Najd.
BLOCKS AND NATIONS
The US-British block is of course dominated by the US, but the British in this world never really accepted the loss of their Empire, and have struggled to maintain their position, together with the states of the White Commonwealth, as a partner rather than a subordinate to the US, and have avoided being drawn into the increasingly united Western Europe. The British have several space colonies of their own: in an amusing historical echo, many of the colonies have large populations of immigrants from…the non-White Commonwealth.
The US is rich if a bit nervous in an era of furriners jetting all over the cosmos and getting up to who knows what. Immigration to the US has been a bit lower with the space colonies being another way out for the yearning-to-breathe-free crowd, but it still attracts talent from all over: it's often easier to find the job you want in a market of almost 300 million people rather than a colony with less than 5 million, and a lot of people aren't up for the rural life, especially if it involves dirt-busting on a planet where the birds have scales and three eyes. Indeed, the biggest problem the US has nowadays is coaxing people to stay in the colonies: Americans love to talk about the frontier, and many of them do go there, but only a few have the determination to make a go of it long-term (note the relatively small population of Alaska). The cost of colonial subsidies is a frequent source of political squabbles. Of course, it gets easier to get people to go once a colony has reached a certain "critical mass" of population and there's a lot more niches to make loads of money without busting your ass...
There are also a number of allied and associated states in Latin America, along with the South Koreans and the Taiwanese, and the Filipinos have been quite enthusiastic about settling under distant suns where they won't have to worry about being hit by a hurricane a couple times a year.
The Japanese-European alliance is increasingly dominated by Europeans as Japan's economy grows more sluggish (they have avoided the "permanent recession" of OTL, but they are still suffering from an increasingly aging population): Europe is dominated by a close French-West German alliance, and is more closely united and top-down organized than OTL, which leads to occasionally grumblings on the part of the Italians and Scandinavians. With the division of Yugoslavia and the Spheres of Influence agreement of 2003 that allowed Austria to join the European Union, today only Finland and Switzerland remain neutral among the European larger-than-postage-stamp nations. (Albania, having collapsed economically and then politically after the great Albanian colonization program on Skanderbeg went pear-shaped, and is currently a UN ward).
European and Japanese colonies tend to be more tightly planned than US-British ones, if not so much as the Soviet ones. They also tend to be less populous, given the relatively sluggish population growth in even France and a greater reluctance to recruit in the overpopulated third world for colonists. With the fading of the WWIII menace and the lack of the British as a "link" between Europe and America, relations with the US are cooler than OTL, although NATO has not (yet, anyway) disbanded. Population growth rates are a bit higher among settlers, generally, (for one thing, the first colonies date to the 50s and cultural mores remain more conservative) and there are also efforts to favor recruitment of groups which _like_ children: the future frontier will probably feature rather a lot of Mormons, among others.
The loosest and most informal of the Blocks is the Third World Block headed by India, which includes Arabs and Africans, Brazilians and Bengalis, and South Africa since the majority of its white population moved to Voortrekker. In spite of the shiny new administrative center built in the Kenyan highlands, the Block remains riven by jurisdictional conflicts and member states drift in and out of the Block on the basis of petty quarrels and whether one of the bigger powers is offering them a better deal this week.
Many colonies tend to be cooperative efforts between multiple Third World nations that otherwise couldn't afford the outlay, but even then most colonies aside from a few "prestige projects" tend to be short on everything save cheap manpower, and many inhabitants of the poorer nations try to get transport as colonists to the colonies of the US or, failing that, Soviets or the few spaces available in the Euro-Japanese block, in all three cases ships being far less likely to explosively decompress en route and first-year survival rates on raw new worlds tend to be a lot higher.
Third Worlders generally only go to Chinese Block colonies if their governments draft them to do so. Although the Chinese have rejected Maoism, they have not chosen capitalism either, and the present regime follows a sort of technocratic Stalinism: with cheap power and food and raw materials from the colonies, they have managed to avoid the fate of OTL North Korea, and their economy continues to grow, although its mostly a matter of more and more Big Steel things and infrastructure rather than value-added products. (They have finally managed to create a carefully nurtured electronics industry, though). More than a third of all space colonists come from China and its few radical-left allies (North Korea, Maoist Nepal, Laos, a few African states…), drafted and shipped en masse to the colonies. It is estimated that death rates on new colonies exceed one third in the first year, but there are always more where they came from, and the Chinese are determined to claim as much of the galaxy as possible for their people.
The Soviet Union survives, the cool-down in the arms race from the mid-60s on allowing a re-allocation of resources to consumer goods, aided by the unlimited raw materials drawn from the space colonies, while the grandeur of the great work of creating Socialism in One Galaxy has restored some of the faded luster of the Communist Regime. (Not that it is very ideologically pure: the State winks at a lot of capitalist activity, and the Black Market has essentially been co-opted and exists in a weird semi-legal limbo, while running one's own business is almost normal on the "Pre-Socialist" frontier. Space is also even better than Siberia as a location for exiling troublemakers, whether Russian, Polish, Armenian, Kazakh, etc. The biggest problem currently (aside from always-restive Eastern Europe) is low birthrates, which as in the European case hampers the development of the colonies and slows economic growth: unlike Europeans, the USSR currently is very energetic in encouraging immigration from third-world countries, although considerations of social order mean that more of them end up in the space colonies than in Russia proper.
ALIEN RACES: SATELLITES, PROTECTORATES, DEPENDENCIES
Soviets still like to think of themselves as defenders of the oppressed (they are on pretty good terms with the Third World Block) and therefore have a great deal of trouble finding ideological justification for what, in the end, comes down to establishing colonial control over several alien races. Of course, that is a problem common to all the major human powers.
Although only about one in two hundred planets with biospheres as advanced as earth have developed intelligent life in geologically recent time, about a half of all habitable planets have intelligent inhabitants. This is because any tool-using intelligence past the Stone Age tend to eventually develop antigravity, and a high percentage go on to interstellar travel. Although most would-be conquerors tend to go after planets already inhabited (empty planets involve back-breaking labor, no slaves, and nobody to ask about local dangers – if it's uninhabited, there must be dangers, no?), sooner or later someone desperate and land-hungry to try comes along, and a fair percentage survive the risks (diseases, parasites, toxic local biochemistry, radiation, weird weather cycles, lack of necessary elements in the soil, etc.), eventually expanding across the planet – to in turn become a prime target for another bunch of alien conquerors. Some long-settled worlds have changed hands many times, and have as many as a dozen resident races arranged in complex social hierarchies.
Aliens are generally either conquerors or conquered. With the exception of lucky races whose biochemistries are so rare and exotic that any invaders quickly get nasty allergic reactions, unpleasant people dropping out of the sky is an unavoidable problem: to keep it from happening, a race must head into space itself and build a badass reputation. The conquerors are those who have an edge, being smarter/quicker/stronger/more adaptable/faster breeding than other races, and above all, ruthless and aggressive. The passive, the slow, the peaceful find themselves laboring in the mines and fields of the conquering races. (Like Aristotle, alien philosophers divide species between "natural" rulers and "natural" slaves – with considerably more biological justification).
Alien empires innumerable have come and gone, as civilizations rise, grow decadent, break apart as their colonies grow to surpass the home worlds in strength. Governments, thanks to easy transportation, are generally planetary, although in a few cases races with very different environmental needs may share a planet. Aquatic intelligences often share planets with air-breathers, since there is little either wants from the other (Due to the difficulty of making spaceship hulls under water, star travelers tend to be air-breathers, but there are exceptions: terrestrials have already run into one shrimp-like race that travel in ships made of something resembling the shells of molluscs, made of special organic secretions). Life is normally oxygen-breathing and carbon-and-water based, although there are a few isolated exceptions. Alien sapience also tends to follow a "Gaussian curve" of sorts: aliens too different from the galactic average for communications (in other words, taking and obeying orders) tend to be eventually exterminated.
Many races are old, old, having spread too far for the inevitable fate of any planet-bound race: slow extinction at the hands of waves of conquerors slowing replacing them over the millennia, or faster at the hands of some natural disaster that either kills them off or reduces them to hunter-gatherer status (hunter-gatherers tend to die off when more advanced races move in). Some have been around long enough to evolve into multiple non-interbreeding species. Some slave races are also wide-spread, travelling with their conquerors: some species have been bred to be better slaves over tens of thousands of years.
The slave trade is part of galactic commerce: alien slaves with special and useful talents sell well. Special foodstuffs, drugs, precious metals, even bulk commodities are sold, and every important planetary capital has a vast market sector, where ships from many worlds unload their cargo. Commerce as well as war is a major part of galactic life, and many races specialize in trade: they are aided by the fact that warfare outside the atmosphere is largely unknown, the speed of antigravity ships, combined with their lack of long-distance weapons, making it truly a mug's game. Space pirates attack weak planets and colonies, not commercial vessels.
There are no known technological species. Scientific thinking, for one thing, is hard: few humans make a habit of it, and some races, such as the Bobbleheads of Delirium (earth names: they communicate by stinks) are even less naturally adept. Furthermore, the importance of anti-gravity tends to close off the developmental paths which lead to science: the physics and behavior of antigrav field generators are so alien to basic Newtonian physics, that their study generally leads thinking about the universe into blind corners. Knowing the positions of the stars and planets is of little importance if you can fly to them, latitude and longitude are unneeded when you can circle your world in under an hour. The early establishment of planetary empires gets rid of the competitive spur of other nations next door (there is conflict with other alien races, but that tends to be a more long-run thing). In any event, no alien race yet encountered has had an scientific revoltion: given the speed of humanity's expansion, it seems unlikely to human thinkers than any such race exists in the galaxy. (Other galaxies may be a different story. Even with hyperdrive, they're a looong way off).
The past may also have been different: earth scientists are a bit puzzled as to why every habitable planet hasn't been settled, given the billions of years of time that have gone by since life first evolved in the galaxy. A Japanese mining outfit on a distant planet may have found part of an answer, having uncovered a mysterious structure of golden metal in five-million-year-old strata on one of the colonies. Currently the Japanese government is keeping it a secret even from their European allies, so the Soviet archeologists which have found an ash layer of as yet unmapped but seemingly vast extent at the five million year level in one of their colonies haven't connected any dots yet.
While there are no races with true science, there are some kinda-industrialized races. Even on Earth in the middle ages, people took at advantage of wind and water power to drive machinery: some races have used antigravity to drive machinery on a massive scale, and produce mass quantities of cheap cloth, steel, household utensils, guns, etc. No complex machinery, trains, rails, electrical equipment – the science isn't there – but a lot of simple goods, useful for trade and for war. And a number of races have come up with some interesting stuff on a cut-and-try basis, such as advanced deep drilling techniques, gas lighting, incendiary weapons (see, Greek Fire) or have even invented the battery (usually used for electroplating). Organizationally, some races are quite sophisticated: the Shamishem bureaucratic caste has been around so long that keeping good records and cross-indexing things has become to some extent genetic, the Porrock traders invented compound interest before humans figured out the bow and arrow, and the X!thraa actually make Communism work. (Most planetary governments are despotic, but there is a lot of variation: there are even a few parliamentary democracies out there).
However, in the end, none of them are anywhere near a military match for the human race.
The tendency of aliens to consider any new species as possible slaves until proven otherwise, their aggressive attitudes developed over ages of clash and bluff and temporary alliance, tended to make conflict inevitable even when humans were as careful as possible: and humans were often not careful. The Chinese and Soviets tend to take the initiative, arriving on alien worlds in colossal armored ships and providing atomic "demonstrations" within window-cracking distance of the centers of government: most alien worlds within a few hundred light years of Chinese and Soviet colonies now have official "observers" at the heart of their governments. Indeed, the Chinese have gone further, and downright colonized some worlds with strategically useful locations or rich mineral deposits or great future agricultural potential: so far they rule through the dominant classes rather than taking the societies apart, but have begun to push communist notions of economic development and industrialization (pre-nuclear age, to be sure).
The other powers have been forced to make "demonstrations" themselves, to convince aggressive races to leave their people alone and keep clear of newly claimed worlds: in other cases they have been dragged into alien quarrels to protect "friendly" races (the aliens have no science of physics or chemistry, but after ages of practice, they know the science of Diplomacy very well indeed). Some alien colonial regimes have involved such brutal subjugation of other species that outraged Third Worlders from former colonies have intervened militarily to overthrow such regimes: given the decentralized nature of the Third World Block, this has happened with no consensus, and has often dragged uninvolved nations into interstellar messes. The US and European blocks have better control of their explorers and colonists, but they also have been driven to interfere, most notable on a planet whose decadent rulers enjoyed such pleasantries as "peasant under glass."
And then there are the individual adventurers who in defiance of international law have gone seeking for planets where they can make themselves kings: these efforts generally do not achieve much except giving another alien species a grudge against humans, since a few hundred or thousand men with machine guns and rocket launchers are not well suited to overthrow regimes which can put hundreds of thousands of well-drilled troops with 18th century hardware anywhere on the planet within hours. Things are particularly messy in the International Zone: given their limited funding, UN forces are not able to patrol the area very effectively, and there are rumors the Saudis have been recruiting mercenaries for some unknown purpose.
Earth governments struggle with the problem of having to deal with hundreds of pre-modern states which thanks to the star-drive are essentially right next door to the Earth. Many are calling for out-and-out Empire, and the Soviet and Chinese are busy establishing an informal one, at least, in their sectors: already gloomy warnings are being issued about how the democracies will be overwhelmed by theoretical huge commie alien slave armies. Some wish to uplift and bring modern science to the backwards, disease-ridden, impoverished alien societies, at least the more democratic and civilized among them (which are which is often hard to tell, given the frequent opacity of alien cultures to human observers): others look upon such proposals as madness. Nerves are not entirely settled by the frequent appearance of alien ships popping up on the borders of the solar system, bearing alien delegates: all looking for alliance with Earth nations, and a little of Earth's marvelous, magical technology.
Although there are many who think in terms of how they can profit from the appearance of these new alien "wizards", a majority are simply scared, angry, and/or humiliated. Many ships are travelling between the capitals of the greater empires, some travelling into distant space beyond human ken. Occasionally, an alien race arises that is not merely ruthless but outright genocidal: previous cases are recorded in many ancient stories and legends, for this is one of the few things that can unite the many warring races of the galactic arm in a single purpose. Although humans are not currently genocidal, they certainly have the capacity to wreck havoc on an unimaginable scale. They are powerful, true, but they are mortal. And although few alien worlds have over a billion inhabitants, there are thousands of them…
SPOILERS: the aliens don't win.