Well said, dan.
So how would the alternate WWII be played up in a world where Central Powers won the WWI?
There needn't ever be a second world war. It's not impossible, but nor is it inevitable.
Would Germany (not a Nazi one, certainly), Austria-Hungary, and Ottoman Empire become major players in this alternate WWII?
One struggles to imagine Germany not being involved, but the other two might not still be about. Austria-Hungary is going to be increasingly a German dependency and may be formally wound up. The Ottomans have better prospects but the time of the CP victory changes the Ottoman fate dramatically.
Again, the survival of the two empires could go either way.
And I remember reading somewhere that if Central Powers won the WWI, then it would be France, Russia, or even Britain that goes Fascist/Nazist, and started this alternate WWII. Would it possible?
A fascist Russia is one fairly likely scenario and a 'fascist' (really reactionary, authoritarian, plutocratic) Britain not by any means impossible. I can see France go rather fascistic, Faeelin-style, but as others point out I can't really see France starting another war whatever government is in power. And why should fascist France be anti-German? It wasn't IOTL.
And if this Central Powers victory comes before 1917, that means no U.S. involvement in an alliance against Germany for WWII.
Dubious. WW1 itself played a role in isolationism ("We made the world safe for democracy and they set fire to it instead"), and imperial Germany might have imperial interests in the western hemisphere and the Pacific. The ambitions of the the silent dictatorship were never exactly modest.
Remember, a CP victory (or even a stalemate) means that Germany is free to go on building u-boats. If you look at what an ordeal 1917 was for Britain, with around 130 German subs to deal with, how will it go in a second war where Germany starts with 300 or even more?
Well, if France is neutral it's going to be a duckshoot, since they can only operate in the western approaches and the moment *RAf Coastal has a decenta nti-sub capability they're toast - unless the war starts only after they develop long-range boats.
Really, the technology and strategic situation was so different in two wars that one can hardly draw a comparison - the only sure thing is that we had learned the few unchanging lessons about convoys, rationing, and maximising food production.
Anyway, who says we have to be against Germany?
What inentive would GB have to go revanchist? WW1 Germany, nearly no matter the scenario, wont be in any position to impose many demands on GB. So for the Britons, it will have been just a further clash on the continent, and in that game, hey, you win some and you lose some...
Not revanchist, certainly, but authoritarian and nasty is perfectly possible. Look at Ireland, India, and Iraq in the 1920s
when we'd won. A WW1 which ends the right way could trap us in a bloody Irish quagmire and lead to harsh crackdowns throughout the empire. Come the *General Strike, the technique is applied at home. Aroma of Ed Thomas, and a disturbing whiff of OTl trends.
I also really can't see Britain turning fascist, since any British defeat in World War I is likely to be along the lines of status quo ante while acknowledging German gains against France/Russia. That's not the sort of defeat that generates nationalist outrage which leads to fascism.
I really don't see the connection between defeat and fascism or, more generally, early 20th century ideological authoritarianism (because I don't know quite what to call Japan). Italy won, Japan won, Romania won, Spain wasn't involved.
Also, given the trends within British Fascism in OTL, it would be more likely to return to Splendid Isolation from Europe and renewed focus on colonial affairs/overseas influence. IMO, fascist Britain is more likely to get into a war with the US over competing spheres of influence then it is to get into a conflict with anyone on the continent.
Now this I sort-of agree with. An alternate WW2 I like to toy with is basically a decaying British Empire that is partially a German creature being bailed out by its German and Japanese allies against the Sino-Russian-American alliance.