This could be a very interesting idea, Maybe something smaller in scale than the Spartacist Uprising can happen in this TL, and both it's failure and the stalling Russian Revolution can be enough to convince party leadership to take a more cautious route.
OTL's Spartakist uprising was really small in scale already, when you count it against the strength of socialist labour in Germany in general.
Maybe steadily adopting a type of Deleonist model that emphasizes both the organization of workers into Unions/Councils and a stuctred political party that competes in the electoral proces or would that be a bit to much out if character?
That's not at all out of character, it's exactly what Luxemburg and Liebknecht were advocating and what the pro-Spartakist Revolutionäre Obleute were doing. Cf. Luxemburg's
criticism of Lenin in 1918.
The big problem is not getting the German ultra-left to be non-Leninist. The big problem is making it behave in a tactical and clever way. Liebknecht and Luxemburg were extremely upfront, honest, outspoken political thinkers (not really political organizers at all), and especially Liebknecht was such a popular icon that he couldn't be sidelined by anyone else who is more sly and scheming. Unless you kill him off like IOTL, but that would disrupt the "low-profile strategy" at once.
That is something I haven't decided upon. The reason I used the Kapp Putch was because of the Rurh Red Army, which in OTL was very decentralized and fractured. I think it (and maybe other worker militias) could have benefitted from some type of central organ.
Well, the Ruhr Red Army was an alliance of anarcho-syndicalists, independent social democrats, and communists. You can not have the latter two split, but I don't see how you can have the FAU integrated and subordinated under a central organ dominated by others - unless you give them great leeway to do whatever they want locally, like in the short-lived Bolshevik-Makhnovist alliance IOTL.
OK, here comes my sketch:
- In her prison cell in Breslau, Luxemburg writes about the Russian Revolution, like IOTL. Instead of lauding the initiative and the will to power of the Russian proletariat and its Bolshevik vanguard and criticising them for unnecessarily curbing democracy and political liberties, she is lauding them for a "good start" of relentlessly pushing the socialist agenda and pulling others in an alliance with them (the Left SRs), then criticises them for abandoning this alliance when in power and thus succumbing to the inevitable fate of Robespierre (I assume Lenin is shot by Left SR Fanny Kaplan?).
- Come the Kiel Mutiny and the SPD jumping on the revolutionary bandwagon and the Spartakists liberated from prison, the leaders of the Spartakist faction urge, in Luxemburg's sense of TTL, the USPD Congress to push for an ambitious (and popular but hopelessly unrealistic) platform, not only with the Constituent Assembly elections in mind but also to pull the working populace and the SPD to the left. They do not yet manage to sway a majority for their demands,and so the USPD goes into the elections with much the same platform as IOTL but the Spartakists continue to campaign and mobilise for their demands anyway. A somewhat duplicitous strategy is undertaken with regards to arms and militancy: while the whole party denounces the arming of right-wing paramilitary Freikorps with tacit or explicit consent of the Provisional Government (Rat der Volksbeauftragten) and the army leadership within the framework of the Ebert-Groener-Pact, local Spartakus groups and Revolutionäre Obleute continue to clandestinely amass weaponry, too, and to train Red Guards / "security services of the workers' councils" / ... in their use.
[This is borderline ASB, but if you want proper "communism" on a path to a fast and thorough victory, you need to tweak a few things.]
- When the terms of the ToV transpire, the Spartakists lead the wave of popular protest from the left. Liebknecht or Luxemburg seizes the initiative and meets with Frossard and Bombacci. The three publicly proclaim their counter-proposal. In German, it is called "Friedensbund der freien Völker" or something of the like (the free peoples' alliance for peace), and it entails the following core ideas: a confederation of socialist states containing a common Bundist control over the socialized war-relevant treasures of the soil (coal, ores etc.), the elimination of all national armies and the formation of a common Bundist "peace corps" which is also to be disbanded once the revolution has triumphed across the globe, in the meantime it defends the Bund against capitalist-imperialist aggression).
The idea is evidently absolutely fantastic and unrealistic. But it re-animates the almost-slumbering workers' councils, whose main and popular call had been "Peace!" anyway. With the Liebknecht-Frossard-Bombacci Plan around (even though Liebknecht is not yet party leader in Germany, Frossard would find it hard to sell it to the entire SFIO, and as for Bombacci's PSI I'm not sure either), they leap back into action behind the slogans "Peace, People's Wealth, Bread and Brotherhood!" (with the first referring to a peace without harsh conditions which punish populations for the crimes committed by their deposed tyrants; the second referring to the socializations; the third always being popular but especially in a situation where the blockade still tries to starve Germany into submission; and the fourth referring to the idea that internationalist unity and unification is the only viable and logical conclusion to be drawn from the Great War, hence the Bund).
The governments of the Entente states are extremely disquieted. The centrist government goes on and signs the ToV anyway, which costs them dearly in popularity, like IOTL, only this time the protest isn't all absorbed by the Far Right.
- With the post-Paris blues befalling the moderate USPD leadership and the Spartakists having gained massively in popularity with their Bundist rejection of Versailles, a new USPD emergency council is called and Liebknect is elected party leader. The most moderate fringe (I'm thinking of Bernstein and the like) leave the party, but most Centrists stay on.
- Bund-inspired feelers are stretched out by the trio (USPD/SFIO/PSI) to various Russian factions, to the new Hungarian government and to the left wing of the Austrian SDAPÖ and their councils. What they'd need now would be a victory in the relative political void that was Central-Eastern Europe. Ideally, Hungarians and Bundist volunteers or troops from (where???? - a trapped Bolshevik army from the Civil War might be awesome, but I have no idea how to get them pushed all the way through Ukraine....) manage to hold off the Romanian advance on Budapest. [This is also borderline ASB, probably already crossing the border.]
- With a first victory in the East blowing into their wings - and their movement for worldwide peace gaining a paradoxically militarist vibe and more first-hand military experience for many -, Spartakists / Bundists from Germany and Austria call together a common council aiming to find ways to unite both countries into one socialist republic. Their governments look on in horror, begin to imprison a few of its leaders and comb the countryside for weapons in the hands of red guards. But since the Spartakists are playing the social AND the patriotic card this time (they're the loudest voice denouncing Versailles and Saint-Germain with their counter-proposal, and now they're aiming seriously at Anschluss; people like Laufenberg and Wolffheim will support the course in droves, too, causing tensions with the principally anti-nationalist leadership circle around Liebknecht, Luxemburg and Levy), government repression against them is by far not as popular and is going to face resistance and obstruction. Any socialist leaders "shot while attempting to escape" will immediately become popular martyrs, not just for the radical left, but in the eyes of a wider populace (think of Robert Blum 1848).
- We still need something to cause this cauldron to bubble over, to cause revolution first in Germany, then very fast also in Austria (the latter is easy if the first is achieved). THe Kapp Putsch doesn't work quite so well because the Far Right wouldn't attempt it in this political atmosphere, and anyway the entire build-up to the Kapp Putsch with the Baltic Freikorps etc. is going to be messed with by Lenin's death and the different course of history from then onwards. Evidently, it is only going to win if there is broad popular sentiment pushing in the general far left direction, which I tried to plausibilise with the Bundist anti-Versailles campaign. So, the Far Left can't win from a defensive position like in the Kapp Putsch. It needs to be on the offensive in general. We need an opportunity. I'm still not sure what exactly that could be, but we need to take into consideration that outside factors only begin to change towards the end of 1920 . A few political murders might not be enough... even a miners' strike might not be enough... will have to think about that.
Either way, when the Revolution comes, it'll be council-backed, and aiming to make the Liebknecht-Frossard-Bombacci Plan a reality. Which is not going to work because Frossard and Bombacci are not in power in their countries. But a revolution in Austria could happen. And if Kun stays in power in Hungary, the three might form the first nucleus of the Bund in reality (and not just in theory). Now the first question is, what do the Entente governments do in the face of a socialist Anschluss (or even Anschluss plus)? (Considering that at least the Italian government might be confronted with an even more militant Biennio Rosso itself...)
Sorry that this did not end up with the idea of an Versailles-embracing communist Germany. It is almost borderline ASB as it is anyway. (But it's been fun writing it so far.)