I don't think anyone here has yet picked up on the fact that the regime in Petrograd in 1917 was not simply "the Provisional Government," so-called. There was a state of "dual power" between the PG, which really had neither a legal nor a broad popular basis, and the Soviets (I hope everyone here knows what a "soviet" was, distinct from the Bolsheviks later appropriating the term for bodies they controlled utterly), mainly the Petrograd Soviet. "Soviet" is the Russian word for "councils." They first formed in the 1905 Revolution. They were committees formed directly by workers in factories and other workplaces, federated into regional bodies. It was the soviets that held real power in the sense that the troops obeyed them--they would only follow an order issued by the PG if the Soviet countersigned it. The soviets were also by far the most democratic and legitimate (if we consider legitimacy to be a function of popular opinion as opposed to elite "people who matter") form of government the Russians had ever known.
The PG's "base," as much as it had one other than sheer pretension, was that the elites, who had lost control of Russia (at any rate key parts of it such as the big cities and huge swathes of the countryside, not to mention the Army itself) clung to it desperately seeking a new way to come out on top again. And foreign regimes--specifically the Entente--much preferred to believe the PG was Russia's real government to facing the reality on the ground, which was that the PG was really little more than a bunch of wannabees trying to pretend they ran things.
Their other advantage was that the Soviets were unsure they could really be the government, full stop. Ordinary Russians were not used to running things on their own.
This was dual power. In the views of people like Trotsky it was doomed to collapse into one resolution or other--either the old elites would regain dominance and ban the soviets as they had gradually done after 1905, then the Provisional Government would stop being "provisional." Or the Soviets would at some point shut down the PG and step forward as the sole governing system. As a Marxist, formerly Menshevik and now coming over to Lenin's side, Trotsky believed the latter could only happen under Bolshevik guidance and would be tantamount to Bolshevik rule.
LordInsane has been posting "A Central East" over a period of years now and hasn't yet fleshed out in detail whether what happens in his version of Red Russia is more one of these or the other--well he has ruled out a Leninist takeover though Lenin does emerge as the most respected single leader, but the Bolsheviks definitely haven't taken over as they did in "October" (actually November by the Gregorian and the slightly different Bolshevik-adopted calendar) OTL, and by "now" in his timeline (sometime in the 1920s) probably the situation has evolved to a state where they can't, in the unilateral fashion of OTL. (Lenin and Trotsky are both dead last time we looked, and Stalin, who is blamed rightly or wrongly for Trotsky's assassination, is in exile and appears to be irrelevant). I think that at this mid-1920s point we have something more like prolonged and perhaps even stabilized Dual Power, though LI does indicate that the Soviets were always at least somewhat diminished relative to OTL and that the Bolsheviks participated in a Provisional Government that was always more widely legitimate than OTL. He has been rather positive toward my suggestions that the Soviets are becoming embedded in a working (if largely unwritten) customary constitution of the Red state, but he is also noncommittal. It's his timeline and I look forward to whatever direction he takes it in, but I'd be excited if the Soviets remain and hold real power.
Again, I want to stress--"Soviet" does not equal "Bolshevik," though Lenin and his followers believed and hoped and tried to make sure it did. A situation where Soviets included diverse factions that held power in shifting balances and had to learn some rough respect for the rights of more or less loyal opposition might include Bolsheviks, but would not be merely their rule...
The only way to "take out the war" was to essentially surrender to the Germans, which is exactly what the Bolsheviks did at Brest-Litovsk. Huge chunks of Russian territory were ceded to the Germans outright. It was a brutally harsh peace, and the only reason any Russians considered the Bolsheviks legitimate after that was that they really were so tired of that war they accepted that peace came at a terrible price. The subsequent collapse of the German Empire mooted the treaty to be sure, but meanwhile the Germans had fostered a great many Whites against the Reds. I believe that was a clear violation of agreements they'd made in the treaty, but it was a victor's peace after all and no government outside Russia regarded the Bolsheviks as legitimate, so no one but the Reds cared about this betrayal. The Entente powers of course stepped right in to support these same former agents of Germany as their clients to supplant the Bolsheviks. Eventually the Bolsheviks won back most of what they'd traded away at B-L.
But the relevant thing here is, how could a PG, even a broader one more committed to at least a pretense of democracy and the popular interest, possibly do as the Bolsheviks did and still be accepted by the Entente powers as a legitimate Russian government? One reason the Bolsheviks got away with it was that their conception of their destiny, as the revolutionary vanguard of the entire world's working classes, was not tied up to Russian nationalism as such. They could see abandonment of huge and crucial regions of the former Tsarist empire as temporary setbacks, to be recovered with interest as the world revolution got underway in war-torn Europe. In a sort of sense, this is exactly what did happen. But without that messianic revolutionism, how could a moderate PG that looked halfway respectable to Western powers behave like that and survive?
Even if the PG could buy peace with Germany at a price not higher than even OTL Brest-Litovsk, and somehow stay in power in the diminished Russia, it is not clear how stable it could be. And I doubt such a regime would be able to recover more than a fraction of what the Bolsheviks eventually did win back.
Of course OTL the price of "winning" back Russia from the Whites was terribly high, both in terms of immediate bloodshed and devastation and in terms of setting the Bolsheviks firmly on the path of totalitarian dictatorship. In "A Central East" the Reds have in fact not yet won back most of their losses, which took the form both of initial annexations by the Central Powers and subsequent White regimes calved off of that remnant. As of the mid-20s LI's Red Russia is severely truncated in territorial terms. (There are signs that they might be on the point of taking in some of their rivals soon). But OTOH, it seems that the Civil War (like ITTL Great War itself) was shortened and involved a lot less devastation, so the Reds have a lot of
people who OTL were killed, as well as a much higher industrial base to rebuild from--I suspect this, as much as the different political evolution that preserves the Bolshevik's rivals along with themselves, is why this Russia is more civil and also successful in economic terms.
If we imagine that instead of patronizing Lenin, the Germans had in a moment of foreboding killed him instead, and that in general the Bolsheviks were so disrupted they never were in a position to pull something like OTL October, I foresee Russia falling into a mess--warlords, rival pretenders to the Tsardom, neighboring regimes from Romania to Japan scheming to carve off territories here and there, puppet governments, and eventually a recovering Germany plotting to invade and take control of the heartland, especially the resource-rich south, by proxy or direct rule. Perhaps out of this chaos some non-Leninist faction would emerge, take charge, and repel many of these threats, but if they can it will certainly not be by means more gentle or less infamous than those the Bolsheviks, culminating in Stalinism, used OTL. I admit they could hardly be less humane (though in my opinion Nazism, for instance, is definitely worse than even Stalinism, for example because it sets up racism as a normative value) but they probably could not not be more effective, and any less effective than the Stalinist accomplishments and Russia winds up being conquered or partitioned (ie, conquered by a diverse collective).
When I want a good Russia wank, I prefer to imagine more effective and more humane Russian Marxists, myself. And I doubt they could have a lot less blood on their hands than Stalin did accumulate OTL.
Another reason I like Central East so much is that I see that possibility being held out there, maybe. (I also like it for reasons that are unrelated to Russia, such as the possibilities it holds out for very reasonable airship wank...
)