So you’re down in a parking lot’s lowest level. You’re all like, “Goddamn this mall’s crowded bullshit weekend sale,” because you’ve been forced into this dank suburban bunker. Just as you find your car, everything shakes. The lights go off. Some parts of the ceiling collapse.
You know this can’t possibly be good. You work your way to the emergency stairs, using your cell phone for light, climbing up to the surface. You assume it’s an earthquake. But it’s not! You open the parking garage door to see the world’s been annihilated.
Congratulations! You just survived a nuclear holocaust by accident.
You’re extra lucky, too, because the prevailing winds are going in the opposite direction, mutating and melting those survivors, while dosing you with about the equivalent of a couple of x-rays. Sure, it ain’t good – but you’re not about to die. You have the unpleasant task of rebuilding the world ahead of you.
So it’s Fallout, Mad Max, and Waterworld all rolled into one
All those things tell the story of the immediate aftermath of an apocalypse. They all assume that such a thing doesn’t wipe out the species. In spite of pessimists’ hopes, humanity cannot kill itself so readily. Pockets of people will survive any calamity. There will be the well-prepared in their bunkers, the lucky ones out of the cities or in remote areas, and the handful of folk wandering around in accidentally nuke-proof parking garages, buildings, tunnels, etc.
And they all have one thing in common: they want to live.
Problem number one: dinner
Worldwide, everyone faces the same set of problems: radiation, food and water security, and preventing attacks from other survivors. They solve these the same way our ancestors once did – by uniting into tribes based on common backgrounds, hunting and gathering for food and water, and avoiding “cursed” radioactive zones, which in this case would largely be big cities and former military bases. The nuclear winter would take its toll, dropping population further. By the time it’s all said and done that first year, there are only tens of millions of people left, putting the world’s population back to about the year 1 AD.
Geography ends up telling tribes how to behave
Extremely cold and extremely hot and dry places are emptied. Good-bye Saudi Arabia and everywhere like it. People congregate in regions with fresh water and decent weather. Sure, some AC repairmen survived the war, but they can’t get access to the materials needed to start up an air conditioning culture again. Remember that to build a single AC unit required components made throughout the world and traded globally. World trade has vanished. The great merchant fleets are a memory now.
So tribes end up living in temperate or tropical zones. Temperate zones have fewer diseases, so these tribes end up living longer. Some of the tribes become raiders, especially in places like southern California, where rain is sparse and farming is hard. They find it easier to attack settled communities to survive. Other tribes settle near rivers, lakes, and floodplains. These tribes establish food and water security early on and grow into proto-states.
So how do then do the North American survivors act?
California’s Central Valley suffers some fallout, but not enough to make it uninhabitable. As radiation drops, the Valley hosts a series of tribes and villages that eventually unite into a single political unit. With American political tradition ingrained in these tribes, it’s a Republic that forms rather than a kingdom. The California Republic extends itself north and south, towards the ruins of Portland and San Diego, rather than attempting pointless expansion into the Nevada desert, which forms a natural border.
Survivors in the Pacific Northwest aren’t numerous enough to resist. They simply don’t have the same growing season and so can’t feed the same population level. They become provinces of the Republic; many join willingly rather than face down California’s rapidly growing armies. California’s resource base is wide enough to allow a varied economy. Over time, it gropes its away back towards industrialization.
While the American West goes full-on Mad Max
In states like Arizona, Colorado, and Utah, where rainfall is slim and farming is difficult, the population density remains low and hunter-gatherers set up shop. Many of them live off raiding one another as well as the California Republic. They are a perennial headache for the Republic’s eastern flank. Their raids force California to send troops to smoke them out. But because of the wide expanses involved, it’s only when California starts to reintroduce the railroad that these tribes are corralled and defeated.
On the other side of things, the Eastern states get to empire-building
On the east coast, heavy nuclear attack leaves most of New England and the Beltway in ruins. It’s out of Virginia, North Carolina, and other southern states, where population densities were lower and therefore more of the population survived, that the first proto-states form. Anarchy prevails and few proto-states are stronger than any other. Different political forms arise; confederacies, federations, leagues, perhaps even a few kingdoms and empires.
Eventually, however, because no great natural barrier exists to prevent expansion, one state overwhelms all others and establishes an Eastern Republic, extending upwards to the Great Lakes and into Canada, where the survivors are too few in number to resist invasion and annexation. This state moves westward likes its for-bearers over the Appalachians.
And it comes up against a powerful state centered on the Mississippi
In middle America, along the Mississippi, a great river network of traders and farmers emerge and unite into an Egypt-style state, highly centralized and focused on the river. This Mississippi state resists the pressures from the Eastern Republic, but as the East industrializes, is left behind in war materials. Eventually, the East conquers the Mississippi for much the same reasons as the North conquered the South during the Civil War. The conquest is just as brutal but brings the Eastern Republic to the Rocky Mountains.
Down in Mexico, the east coast unites while everyone else shatters
Mexico’s geography is more broken up, so city-states and kingdoms emerge in relative isolation from one another. On the east coast come a series of naval powers eventually united into a single one, perhaps centered around Veracruz. This Veracruz state competes with the Eastern American Republic for dominance of the Gulf of Mexico. Ample oil supplies allow them to go toe to toe with the Americans. Several wars are fought over Texas for that reason.
In the western and southern reaches, Mexico fragments. Various city-states and fiefdoms compete with one another much as they did prior to the coming of Europeans. As soon as one grows dominant, others unite to strike down the top dog. No great state is able to come of the chaos. In the ruins of central Mexico, once home to the great capital city, anarchy prevails. Veracruz finds stability in playing these city-states off against one another; over time, however, the fighting spills over the border and Veracruz feels compelled to invade and occupy the area.
Poor Canada ceases to exist
California moves north into what was once British Colombia, overrunning any settlements and cities there. The American Eastern Republic, as we’ve seen, expands into Quebec and Ontario, which, without outside protection, can’t stand up to a power with access to the higher population densities of the eastern American seaboard.
Finally, world trades start to trickle back in
By now, it’s been perhaps one hundred years. Trade networks are reforming. Europe is pure chaos, but happily trades with the Eastern Republic for raw materials and weapons so they can continue to fight their endemic wars. The Eastern Republic draws closer to Europe. Meanwhile, California reconnects with Asia, where a united Japan desperately needs the raw materials it can provide. California starts to colonize the American West at long last, taking coal, iron, and other raw materials from the mountains for trade with Asia. This brings them into contact with the power of the Eastern Republic.
The battle for supremacy happens in the Rockies
Both the Eastern Americans and the Californians race to secure the raw materials of the American West. It becomes a military zone of back and forth conquests. The local tribes are caught up in the mix, conscripted or wiped out, as their cultures cease to exist. Over time, the wars favor the Eastern Republic, with its bigger population and higher resource base. But California is a tough nut to crack. Eventually, war weariness results in a partition of the West, with jagged borders drawn with hardly any consultation of the few remaining locals.
Thus an uneasy truce forms while a cold war grows in Mexico
Hoping to outflank one another, both California and the Eastern Republic search for Mexican allies. It’s largely Veracruz that they seek to win over. Veracruz chooses California as a natural partner, since California is both the weaker of the two American successor states and further away. The imperial pretensions of the Eastern Republic are by now clear.
Both sides also try to win influence and allies in the Caribbean’s successor states. Cuba is the glittering prize. The Eastern Republic invades Cuba and annexes it, building a network of Caribbean provinces and military bases to contain the allied powers of Veracruz and California. They also pour money and weapons into the shattered polities of southern and western Mexico, stirring up trouble against Veracruz’s western flank. This forces Veracruz to finally unify temperate and tropical Mexico.
Here the geopolitics starts to stabilize
By this point, California is strong enough to resist expansion from the Eastern Republic. The two reach an accommodation and accept that the old United States will never be again. California pushes its border down through Baja and into the deserts on old Mexico’s west coast, which form a handy barrier between it and Veracruz. World politics starts to come back into play; by now, perhaps a European power is the global hegemon. Technology has roughly worked its way back to the 19th century with bits of high tech junk still lying around, but nobody’s yet to the point where they can develop nuclear weapons again.
Wars continue, including several global ones, until a new world hegemon emerges to enforce a new world order
World War II was the great geopolitical stabilizer; it anchored the international system between the United States and USSR until the latter’s collapse. The post-apocalyptic world will be no different. As the memory of the nuclear holocaust fades, humanity’s political units will once again engage in an epic struggle that will shatter most but leave a few standing above the rest. With America divided, it’s unlikely the new hegemon will come from there; California and the Eastern Republic would quite naturally join opposite sides in a world war and bloody one another since both would still seek to dominate the former United States. Whoever the hegemon ends up being, it would be based in the Old World.
This would go to show just how lucky the English colonists and their descendants really were to enter North America when it’s political units were too immature to resist conquest. Alas, after an apocalypse, that advantage would be lost. Its new destiny would be to play second fiddle for some far away power.