Most left tendencies considered this concept, and the premises on which it was based, as either a fantasy, or objectively a call for counter-revolution. The overthrow of the bureaucratic dictatorship could only lead to a restoration of capitalism: that was the assumption.
These objections were unfounded. Trotsky’s prognosis of political revolution, like his analysis of the contradictions of Soviet society, appear as one of his most brilliant contributions to Marxism. Since 1953, we have witnessed a chain of revolutionary crises in Eastern Europe: GDR June 1953; Hungary 1956; Czechoslovakia 1968; Poland 1980-1981. One can discuss whether similar crises didn’t also occur in China, both in the nineteen sixties and the nineteen seventies. (Mikhail Gorbachev himself calls his perestroika a revolution and compares it with the political revolutions which occurred in France in 1830, 1848 and 1870.)  In all these concrete revolutionary processes, there was no prevalent tendency to restore capitalism. This did not only result from the objective fact that the overwhelming majority of the combatants were workers who have no interest in restoring capitalism. It was subjectively determined by the very demands of these combatants, which in Hungary set up workers’ councils with the Central Workers Council of Budapest leading the struggle. Similar development occurred in Czechoslovakia and in Poland. The line of march of the political revolution in the USSR will be quite similar.
On the other hand, it cannot be denied that attempts at self-reform of the bureaucracy have been many-the most spectacular of them being the introduction of workers’ self-management at factory level in Yugoslavia in 1950. While often instrumental in triggering off a “thaw” of the bureaucracy’s stranglehold on society and enabling a revival of mass activity and mass politization at various degrees, these attempts have always failed to solve the basic ills of these societies. This was especially true for the historically most important of these attempts, the one initiated by N.S. Khrushchev in the USSR. Indeed, today most of the “liberal” and “left” Soviet historians and intellectuals agree that the reason for the failure of Khrushchev was insufficient activity from below. This, incidentally, is also Gorbachev’s official version of the Khrushchev experience.
So the historical balance-sheet is again clear: attempts at self-reform can start a movement of change in the bureaucratized workers’ state. They can even facilitate the beginning of a genuine mass movement. But they cannot bring about a successful culmination of such change and movement. For this, a genuine popular revolution is indispensable. Self-reform of the enlightened wing of the bureaucracy cannot be a substitute for such a revolution.
The bureaucracy is a hardened social layer, enjoying huge material privileges which depend fundamentally on its monopoly on the exercises of political power. But that same bureaucracy does not play any indispensable or useful role in society. Its role is essentially parasitic. Hence its rule is more and more wasteful. It tends to become the source of a succession of specific economic, social, political, ideological-more crises. Hence the need to remove it from its ruling position is an objective necessity for unblocking the march forward towards socialism. For this, a revival of mass activity, in the first place political activity of the working class, in needed. While a revolution will have many implications in the field of the economy, it will basically consolidate and strengthen the system of collective ownership of the means of production and of socialized planning, far from overthrowing it. That is why we speak of a “political revolution” instead of a “social revolution.” 
To a large extent, the bureaucracy rules in function of the political passivity of the working class; Trotsky even said through passive “tolerance” by the working class. The historical-social origins of that passivity are well-known: the defeats of the international revolution; the pressure of scarcity of consumer goods and of lack of culture born from the relative backwardness of Russia; the consequences of the Stalinist terror; a disappointment of historical dimensions, leading to a lack of historical alternatives to the bureaucracy’s rule. But the very progress of Soviet society during the last half century, achieved on the basis of the remaining conquests of the October revolution and in spite of the bureaucracy’s misrule, slowly undermines the basis of that passivity. The stronger, more skilled and more cultivated becomes the working class, the greater its resentments and expectations clash with the slow-down of economic growth and the manifold social crises which the bureaucracy’s misrule and waste provoke. So conditions emerge which tend to revive the working classes’ activity.
Timothy Garton Ash quotes a remarkable memorandum by the new Polish Prime Minister, Mieczyslaw F. Rakowski, which concludes with the prediction that if the “socialist formation” does not find the strength to reform itself, “the further history of our formation will be marked by shocks and revolutionary explosions, initiated by an increasingly enlightened people.” Indeed. But as Ash himself clearly indicates, in spite of his favoring reforms moving towards a restoration of capitalism tempered by a “liberal” democracy, the difficulty lies precisely in the social correlation of forces: the working class is not ready to pay the price for a return to capitalism, i.e. massive unemployment and inequality. So you can’t have generalized market economy plus political democracy. You can only have partial market economy plus political repression. So you can’t have radical reforms. So the likelihood that you’ll have a political revolution is growing. Ash himself rather cynically concludes: “It seems reasonable to suggest that the reform has a rather higher chance of minimal success-that is, of averting revolution-if only because of the further diversification of social interests which it will promote. The freeing of the private sector, in particular, means that Hungary might yet have an entrepreneurial bourgeoisie that will go to the barricades-against the revolting workers. Capitalists and Communists, shoulder to shoulder against the proletariat: a suitably Central European outcome for socialism. To estimate the percentage chance of peaceful transformation, by contrast requires only the fingers of one hand. 
Yet, precisely because the bureaucracy is not a new ruling class but a parasitic cancer on the working class and society as a whole, its removal through a political revolution by the workers does not require the type of armed conflict which until now has accompanied revolutions in class societies, including modern capitalist ones. It is more in the nature of a surgical operation. This was confirmed in the case of Hungary 1956 which went the farthest towards a victorious political revolution. A significant part of the CP apparatus and practically the whole army went over to the camp of the workers (of the people). Only a tiny handful of secret police agents opposed arms to the victorious masses in open provocations, thereby provoking an overt conflict (and their own sad fate) which otherwise could have been avoided. In Czechoslovakia 1968 a similar trend was set in motion. In fact, in all cases of such political revolutions witnesses up till now, only foreign military intervention could prevent it from becoming victorious nearly without bloodshed. One does not see what force could replace such a foreign intervention in the case of the USSR, probably not the Soviet army. And the capacity of the KGB to repress 265 million people seems dubious to say the least.
History has also confirmed the utopian character of the idea that the construction of socialism could be fully achieved in a single country or a small number of countries. It has confirmed that the USSR (and the so-called “socialist camp”) cannot escape the pressure of the world market (or international capitalism): the pressure of wars and of the permanent arms race: the pressure of constant technological innovations; and the pressure of changing consumption patterns for the mass of the producers. But far from being an unavoidable result of that pressure, the bureaucratic dictatorship undermines the revolution’s objective revolution in the USSR and Eastern Europe would strengthen considerably that resistance. It would make new advances towards socialism possible. But we should not fall into the illusion that it could even so, actually achieve a classless society of its own, independently of revolutionary developments elsewhere.