I thought this was related to our discussion following Ben’s article in defense of radicalism, specifically seen as a response to those who use historical failures as an argument against revolution. It’s from Deleuze in conversation with Negri in Futur Antérieur in 1990. I think it can also be found in a collection of Deleuze essays and interviews called Negotiations. Maybe you will find it interesting as well:
The thing is, I became more and more aware of the possibility of distinguishing between becoming and history. It was Nietzsche who said that nothing important is ever free from a “nonhistorical cloud.” This isn’t to oppose eternal and historical, or contemplation and action: Nietzsche is talking about the way things happen, about events themselves or becoming. What history grasps in events is the way it’s actualized in particular circumstances, the event’s becoming is beyond the scope of history. History isn’t experimental, its just the set of more or less negative preconditions that make it possible to experiment with something beyond history. Without history the experimentation would remain indeterminate, lacking any initial conditions, but experimentation isn’t historical. [...] It’s fashionable these days to condemn the horrors of revolution. It’s nothing new; English Romanticism is permeated by reflections on Cromwell very similar to present-day reflections on Stalin. They say revolutions turn out badly. But they’re constantly confusing two different things, the way revolutions turn out historically and people’s revolutionary becoming. These relate to two different sets of people. Men’s only hope lies in a revolutionary becoming: the only way of casting off their shame or responding to what is intolerable.