First, in Europe, the key PoD (from
this thread) is that the Franco-Prussian war begins differently, as Baden seeks to join the NGC, leading to a border dispute in France, leading to a larger war with the other German states -- save Bavaria. So while the war is mostly the same as OTL in the important aspects, it differs in the aftermath including unification of the German states
except for Bavaria (and Austria, of course), under much Hapsburg influence.
This leads to continued tensions between Germany and Austria-Hungary, as the former sides with Russia over the latter in the aftermath of the Russo-Turkish War in 1878. That brings me to ideas in
this thread, expressed by Onkel Willaims:
Russia gets a better deal, but eventually still feels short-changed by Britain, France and Austria-Hungary. Russia threatens war, but their bluff is called since they are exhausted from the war and Germany doesn't feel liking denuding their western border an inciting French aggression for the Balkans and so the two back down. Both are pissed that Austria-Hungary was more supportive of the French-British-Ottoman alliance then the position of Russia and didn't support war. Conversely, Austria-Hungary will be pissed that Bismarck supported the interests of St. Petersburg rather than those of Vienna.
The alliance breaks down in 1879. Russia, realizing Germany is the only friendly power to turn to, form a dual alliance with them. In the early 1880s Italy is easily convinced into joining the alliance since both of its competitors (France and A-H) are enemies. Romania and Serbia are probably easily convinced into joining too since they want chunks of A-H. Bulgaria will therefore be in the other camp which means Greece will join with the dual alliance.
Eventually we should get something like this:
Germany, Italy, Russia, Serbia, Romania, Greece vs. France, Austria-Hungary, Great Britain, Bulgaria, the Ottoman Empire (and perhaps Japan).
I would add Alexander II surviving in 1881, allowing him to further modernize Russia in the 1880's.
That actually brings me to East Asia (somewhat inspired by
this thread). In 1871, it is the US that manages to open Korea diplomatically, after the Gangwha Expedition. Korean modernizers in TTL are less beholden to Japan, as the US engages the country as well. But traditionalists also have an asset -- as China struggles with Japan over "influence" in Korea, the former reaches a formal alliance with Russia. The crown prince Sunjong and Prince Ui die young, meaning Gojong's other sons (still young) are not of his reformist wife, Queen Min (she, at least, is not killed in 1895 as OTL).
To add to this still more, Abdur Rahman Khan's death in 1901 leads Afghanistan to drift noticeably into Russia's orbit. Oh, and Russia makes overtures to Persia for a defensive alliance against the Ottoman Empire.
Meanwhile, in Europe...
Germany will start massively supporting pan-German nationalist parties which will want to establish a Greater Germany without the Slavic parts of the Austro-Hungarian Empire. Serbia will obviously support the South Slavic Serbs, Croats, Bosnians etc. while Romania will support Romanian separatism in Transylvania. The Austro-Hungarian Empire will be highly unstable although Anglo-French investment will help them to industrialize faster. I think there will be a new Ausgleich with the Czechs which will make the country a Triple Monarchy although instability will still wrack them.*
The Balkans will be very polarized with Serbia, Greece and Romania opposing Bulgaria and the Ottomans... The Ottoman Empire will try to reform and France and Britain are likely going to waver between propping up the Sublime Porte and making their own plans for partition which will involve their own Balkan proxy Bulgaria. The Ottomans will cling onto Britain and France for fear of Russia, but won't be an effective ally IMHO, especially once Austria-Hungary collapses... which would force the Ottomans to fight in the Balkans and the Caucasus.
*edit: I think Hungary would accept another Ausgleich which would limit its powers, but also prevent it from becoming a Russo-German puppet.
A crisis likes this leads to war in Europe in the early 1900's -- that, and the assassination of Gojong in Korea. His oldest son is not yet of age, leading to a crisis between the reformists like Queen Min, friendly with powers such as the US, Japan, and Britain; and traditionalist ministers, allied with China, and Russia.
So there you have it -- a global war extending across Europe and Asia:
Germany, Italy, Russia, China, Serbia, Romania, Greece, and possibly Afghanistan
vs
Austria-Hungary, Bavaria, Bulgaria, France, Great Britain, the Ottoman Empire, Japan, and possibly the United States
EDIT ADD: Oh, and the acronyms? It's "Plausibility Check and Tying Up Loose Ends"
