Quite fascinating and interesting, and your usual high-quality stuff, OW.
It is most interesting how the triumph of the 1848 revolutions borne out much good and some bad. While it brought the utopian outcome of accelerated global industrialization bringing affluence to much larger swaths of the world than OTL (TTL 1930s are more or less the socio-economic equivalent of our 1990s, as globalization goes), and it avoided the genocidal horrors of Nazism and Communism, it also fostered to a lesser degree the dystopian outcome of much-larger World Wars with unprecedented conventional bloodshed.
As I expected, Britain, Russia, and Japan have been cast down, and currently only the superpowers of America, China, and CP-led Europe remain. I predict a) the swift end of the Chinese-American alliance of convenience, since with the demise of their common enemies (Japan and CP colonial empires), they turn from partners to competitors in the Pacific b) the swift unification of Europe, Russia, and the Middle East in a tight federal EU framework under German-Italian-Spanish leadership, since the last Anglo-Russian challenge to that hegemony has been cast down c) the independence of India and its rise to global great power in its own right d) Britain and Russia have been administered their third knockout blow, and the lesson should stick, as it did for France e) Japan, too, is probably cowed for good, as it is trapped in the Chinese-American vise.
The three World Wars (I reckon the ACW and the Second War of Spanish Succession as TTL's WWI) have ushered it in a tripolar superpower world, with an up-and-coming India as fourth player, and that geopolitical setup seems quite stable and lasting, all the way to the stars.
Some suggestions for the world to come:
Given this world's globalized industrialization and much larger pool of educated citizens, I expect scientific and technological development to be much quicker than OTL. Say a couple decades in everything. By the time 2010 rolls in, it sould have an hard sci-fi look. Early cybernetics, fusion power, genetic engineering (this world hasn't known Nazism, so it won't have any taboo against eugenetics and "designer babies"), robotics, advanced materials, etc.
Likewise, culture is going to be more globalized, with an early rise and larger diffusion of the Net, and Europe, America, and China (perhaps India, too) fighting to dominate popular culture.
As a side effect of the above, space colonization should be much more accelerated. I dunno if any great powers was experimenting with missile technology during GW3, but once someone does, and puts a satellite in space or launchs an ICBM, the space race should start in earnest, with all superpowers taking part eagerly. I predict satellites and humans in orbit in early-mid 50s, Moon landings in early-mid 60s, permanent space stations and Moon bases in early-mid 70s, Mars landings in late 70s or early 80s, Lagrangian Points bases and Mars bases in late 80s or early 90s, expeditions to Jovian moons in late 90s, expeditions to Saturn moons in the 00s, perhaps first serious planning and attempts to large-scale colonization and exploitation of space resources, build orbital habitats, and terraform Mars and Venus in the 00s.
It won't be just a shiny utopia: with all the extra industrial and consumerist affluence, I expect environmental problems to become even much worse than OTL: a kickass global warming in the late 20th century and such. Of course, with a less Balkanized world under the lead of 3/4 superpowers, taking serious steps to redress environmental problems would be slightly less complex, but by no means easy. Perhaps this fuels efforts at recycling, "green" technology, nuclear and by the turn of the century, fusion power.
With all the extra global affluence, and the modernizing effects of the GWs, I expect the 1960s sexual revolution and youth counterculture to hit the world on schedule, and to be even more forceful than OTL. Hard to say what aspect youth counterculture would take, in this globalized world with limited totalitarian ideologies (except Russian fascism). Quite possibly, given the rising environmental problems, "green" neo-Paganism in the West and neo-Taoism in the East.
With a powerful Ottoman Empire, Islamism should be much less of a problem. And with later and harsher Reconstruction of the South, and the superpowers staying more right-wing in some ways (monarchical EU an China, more imperialistic USA), the ATL equivalent of the Reaganite revolution is butterflied away.
Now, all the three superpowers have quite sizable colonial empires, whatever label USA and China stick on their vassals and protectorates, and none is as remotely exhausted as OTL European powers were. Also all three big guys have a stake in the game, so they are less likely to actively support anticolonalism across the board as much as OTL russia and China did (although India is likely to do so). However hypocrite attempts to steal the stuff of the other guys by supporting rebellions in the other empires while fighting to keep theirs are gonna happen, in Africa and SE Asia. So Decolonization should be much slower and more resisted, and likely unsuccessful in some places. E.g. I expect most of the Maghreb to stay bound to and be assimilated to Europe, Philippines and New Guinea to do so with America, etc.
I also expect America to be even more bold and absorb other valuable chunks of Latin America. E.g. Colombia and Venezuela. And I expect Australia and New Zealand to "receive an offer they can't refuse" and sign the same American Dominion confederal deal that Canada got.
