Real living examples of revolution are the test of any theory. May 1968 was such a historical example. These events reveal that defeat of the working class has not come about by such a thing as the "strong state" but by the ineptitude of the reformist and Stalinist leaders who were not prepared to mobilise the full force of the working class.
For there to be a revolution does there have to be violence? To the sectarian mind the answer is always in the affirmative. Marxists look at the question in a more rounded out manner, looking at the many factors that come into play: the balance of class forces, the nature of the leadership of the working class, the tactics and programme adopted, and so on.