The Prophet Unarmed isn't, however, just about a piece of history which increasingly seems to be dwindling away after the fall of the Soviet Union and the beginning of a new century. It addresses fundamental issues: the nature of revolutionary leadership, the role of organization in relationship to material circumstances, what it means to be politically in the working class, with the working class, in its vanguard, or standing above it.
The book deserves its great reputation, and in style and content is worthy of the dramatic and tragic events it chronicles. Without effort, it renders ridiculous both the view still held by a few that Trotsky and Stalin were engaged in a dispute over "line" in which Stalin's arguments triumphed, and the now much more prevalant lazy liberal cynicism that says the fight was over nothing more than personal ambition. It grapples more seriously with harder questions. How did a party as democratic, contentious, and rooted in the working class as the Bolsheviks end up acceding to a bureaucratic dictatorship? What does this submission, and the submission of the once-ungovernable Russian people, tell us about the road to genuine socialism and (the same thing) genuine democracy?
The opening chapter contains an answer to the first question as convincing in all its nuance as any I've heard or read. Deutscher describes the effective destruction of the Russian working class and of Soviet democracy by the civil war:
The nation ruled by Lenin's party was in a state of near dissolution [by 1921]. The material foundations of its existence were shattered. It will be enough to recall that by the end of the civil war Russia's national income amounted to only one-third of her income in 1913, that industry produced less than one-fifth of the goods produced before the war... that the exchange of goods between town and country had come to a standstill, that Russia's cities and towns had become so depopulated that in 1921 Moscow had only one-half and Petrograd one-third of its former inhabitants, and that the people of the two capitals had for many months lived on a food ration of two ounces of bread and a few frozen potatoes and had heated their dwellings with the wood of their furniture...He describes the Bolshevik resort to one-party rule in the absence of any real alternative:
It was a grim and paradoxical outcome of the struggle that the industrial working class, which was now supposed to exercise its dictatorship, was also pulverized. The most courageous and politically-minded workers had either laid down their lives in the civil war or occupied responsible posts in the new administration... Masses of workers fled from town to country during the hungry years... The dispersal of the old working class crated a vacuum in urban Russia. The old, self-reliant and class-conscious labor movement with its many institutions and organizations, trade unions, co-operatives, and educational clubs, which used to resound with loud and passionate debate and seethe with political activity - that movement was now an empty shell. 
The Bolshevik party had the usurper's role thrust upon it. It had become impossible for it to live up to its principle once the working class had disintegrated. What could or should the party have done under these circumstances? Should it have thrown up its hands and surrendered power? A revolutionary government which has waged a cruel and devastating civil war does not abdicate on the day after its victory and does not surrender to its defeated enemies and to their revenge even if it discovers that it cannot rule in accordance with its own ideas and that it no longer enjoys the support it commanded when it entered the civil war. The Bolsheviks lost that support not because of any clear-cut change in the minds of their erstwhile followers, but because of the latter's dispersal. They knew that their mandate to rule the republic had not been properly renewed by the working class - not to speak of the peasantry. But they also knew that they were surrounded by a vacuum... Deutchser also describes how one-party rule became incompatible with the toleration of factions within the party (how else to stop opponents of Bolshevism from simply signing up as members?), the ban on factions became incompatible with real internal democracy and freedom of dissent (what is collective opposition to current policy but the act of a faction?), and the suppression of dissent led directly to first bureaucratic and then one-person dictatorship:
The single-party system was a contradition in terms: the single party itself could not remain a party in the accepted sense... The party maintained its discipline, not its democratic freedom. If the Bolsheviks were now to engage freely in controversy, if their leaders were to thrash out their differences in public, and if the rank and file were to criticize the leaders and their policy, they would set an example to non-Bolsheviks... No body politic can be nine-tenths mute and one-tenth vocal. Having imposed silence on non-Bolshevik Russia, Lenin's party had in the end to impose silence on itself as well. Yet, even after the civil war, "the logic of the single-party system might... never have become explicit, or the system might even have been undone by the growth of a workers' democracy, if the whole history of the Soviet Union, encircled and isolated in its age-old poverty and backwardness, had not been an almost uninterrupted sequence of calamities." 
Deutscher correctly blames material circumstances for Bolshevism's degeneration without denying that, in the famous line of Victor Serge, the "germ of all Stalinism" was (with "a mass of other germs") there from the beginning. He acknowledges that the party's "moral self-reliance, its superiority, its sense of revolutionary mission, its inner discipline, and its deeply ingrained conviction that authority was indispensible to proletarian revolution - all these formed the authoritarian strands in Bolshevism" , strands which enabled 1917's vanguard of the working class to become its slave-driver and enforcer of famine by 1928 without a major split or the eruption of widespread rank-and-file revolt. (Trotsky's supporters were crushed mostly without blood; the massacre of the Bolshevik Old Guard came later, in the 1930s.)
An understanding of this history in all of its contradictions is essential for anyone wanting to pursue the kind of revolutionary project at which the Bolshevik Party had more success than anyone before or since. But I do not think too many lessons can be drawn from the simple fact that the ability and willingness to seize power is a double-edged sword. Humanity and the Earth desperately need fundamental change, and revolution is a violent act - this is something with which we just have to deal.
We can be more directly guided, I think, by leaving aside temporarily the revolutionary liberty that was lost, and looking at what replaced it. In this examination, however, we will have to be more critical of Deutscher.
The last chapter of The Prophet Unarmed contains Deutscher's discussion of the nature of the Stalinist state. If my view and that of the International Socialist Organization that the Soviet Union was a state capitalist society is, on this question, to the left of Trotsky (who viewed it as still a workers' state, however twisted), then Deutscher's view is to the right. Deutscher says of Trotsky:
Because ultimately he identified the process of revolution with the social awareness and activity of the toiling masses, the evidence absence of that awareness and activity led him to conclude that, with Stalinism victorious, 'the film of the revolution was running backwards' [towards capitalism] ... The film was not running as... the makers of the revolution had expected: it was moving partly in a different direction - but not backwards. "The great transformation of the Soviet Union in the 1930's" by forcible industrialization and collectivization of agriculture, Deutscher continues, "was Trotsky's victory in defeat", despite the incredible human cost, for it constituted a "second revolution" establishing a real material basis for socialism. 
Trotsky's identification of revolution with the self-activity of the working class is right, and Deutscher is wrong here. The basic tenent of Marxism has always been that "the emancipation of the working class must be the act of the working class itself." No bureaucratic dictatorship can substitute.
What, then, did Stalinism represent? Deutscher is on safe ground in pointing out the obvious flaws in Trotsky's early view of Stalin as leader of an unstabled, wavering faction, "balanced between right and left", without "broad social backing."  And he is right, too, that this flawed view followed from Marxist tradition - taking for granted not only the obvious fact that Stalin did not represent working class liberation, but also the assumption that a restoration of capitalism could come only from the farmers and traders and not within the Bolshevik party.
The fault lies with that latter assumption, shared by Deutscher and Trotsky - that only private capital and not the bureaucracy constituted a potential new ruling (capitalist) class. In fact, the bureaucracy's coherence as a class explains Stalinism's triumph over opponents both right and left, and its ability to transform Russian society.
Trotsky's mistake also explains his repeated hesitancy and fatal delay in taking his struggle first to the party rank-and-file, then to the Russian working class outside the party. Deutscher writes, voicing Trotsky's views:
The bureaucracy was not yet a new ruling or possessing class... the basic conquests of the October Revolution were intact, the Soviet Union remained essentially a workers' state, and the old party was still in its own way the guardian of the revolution. Consequently, the Opposition must not sever its links with it, but must continue to regard itself as belonging to the party and defend with the utmost loyalty and determination the Bolshevik monopoly of power.From that starting point, the dilemma was indeed insoluble. It is not obvious that going outside the party would have been a solution either - the devastation of the Russian working class to which the Trotskyist Opposition might have appealed remained a material reality, and to the extent there had been a recovery by the late 1920s, it was offset by the demoralization and depoliticization that accompanied years of one-party rule. But any revolt bound by the rules set by the Stalinist party machine was hopeless.
From this it followed that the Opposition must not seek to recruit support outside the party. Yet it was not allowed to recruit it inside either. This was an insoluble dilemma. 
This is partly a dispute about the nature of the Soviet Union, which has been written about at great length. But it is also a dispute about the definition and purpose of a revolutionary party.
What this history should tell us is that it is wrong to identify too closely the vanguard of the working class - its core of leaders and fighters who remember its history and can generalize from that experience to take its struggle forward - with "the" revolutionary party. That the Bolshevik party had been in every sense the vanguard of the class up through 1917 and after did not mean that it retained this role, and a split from the party, futile or not, would not have meant a break with the revolution. The two were far from identical - even well before Stalin's victory. Moreover, Deutscher's persuasive argument that the one-party policy was, necessarily, destructive not only of democracy in the abstract but of the working-class movement including its vanguard, has implications even absent state power. The party can only be a genuine vanguard through a dynamic interchange with a political milieu around it, in which different political views can find organizational expression without having to fear consequences beyond the risk of error - consequences in the form of political repression or the sort of fear of complete alienation from "the" party and emotional abuse that even sects with no capacity for violence have exercised quite effectively.
The International Socialist Organization has always correctly viewed the claim of any grouplet with a membership in the hundreds to be the one and only vanguard as absurd - and for this reason refrains from calling itself a "party". I think the same sort of distinction between organization and vanguard needs to be made clear even where a mass revolutionary party exists.
But I am committed not just to the project of building a revolutionary party, but also to the view that a centralized organization is a necessity for deep and fundamental reasons - to be the material embodiment of class consciousness, in Georg Lukacs' words the "mediation between humanity and history". Can this be reconciled with a strong emphasis on the distinction I've just been defending?
I'm still thinking about these issues, but I believe the answer is yes - we should see the consciously revolutionary leadership of the working class as playing the fundamental historical role, while the party is its tool. A tool which is more effective the more closely its membership overlaps with that leadership, but which can approach identity with that leadership only asymptotically even in the ideal case.
[When I started this blog, I meant to write some kind of review or collection of thoughts on every political book I read, to help ensure that I'm getting something out of it and will retain it. That hasn't been happening, but I hope this is not the last similar post.]
 pp. 4-5 (in the 2003 Verso edition)
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