What do the victims of tyranny owe each other? In this paper, I examine whether they can be condemned for betraying their friends, and I do so through a novel interpretation of Judith Shklar’s political thought. Shklar is a widely acknowledged and significant influence on non-ideal theory and political realism. However, there is also a previously unnoticed transformation between her early and mature work, for although she remains a sceptic her approach to moral conflict changes from value pluralism to value monism. In addition, it is only in her mature work, as a monist, she believes tyranny cancels obligations of justice. I argue here that Shklar’s monism fails, and this in turn has important implications for political realism and non-ideal theory. While attention has been focused on developing a sceptical critique of ideal theory, this interpretation of Shklar’s work illustrates that greater awareness is needed of the pitfalls of monist strands of scepticism.