In his wide-ranging and thought-provoking analysis of war and political violence in twentieth-century Europe, Ian Kershaw contrasts the immense violence wrought in Europe in the first half of the century with its relatively pacific history in the second half. Resisting the temptation to think of the violence of the first half of the century as a dysfunctional interruption to an underlying tale of economic, social and political progress, the author poses three astute questions concerning: (i) the causes of state-sponsored violence; (ii) the reasons why some states presided over low levels of violence while others presided over levels that ‘soared into the stratosphere’; and (iii) whether there was something qualitatively new – or ‘modern’ – about that violence. Kershaw describes his piece as ‘thinking aloud’ and I read it in that spirit. I find myself in broad agreement with what he has to say, although we probably disagree over matters of emphasis – for example in respect of the significance of violence perpetrated by European states in their colonies, or the propensity for violence of liberal democratic states. I suspect that there is more principled disagreement about the salience of ‘ideology’ in fomenting the mass violence of the twentieth century. I have organised my responses according to the three stages of his argument; I end by considering the nature of ‘peace’ in Europe in the second half of the century and by offering a few reflections on the conceptualisation of political violence.