Paul Kelly pays scant attention to the so-called ‘democratic peace’ thesis that has played a major role in recent International Relations scholarship, a lacuna which we regard to be serious. Our paper investigates the normative background to the connection between democracy and peace, commonly associated with Immanuel Kant. We argue that attention should be devoted instead to the critique of international conflict found in the writings of Thomas Paine, who (unlike Kant) offers a politically grounded account of both why peace among nations is desirable and how that might be achieved. In particular, we consider Paine's views on democratic peace through the lens of his goals of eliminating the tyranny of kings and aristocrats and of ameliorating the material conditions of the poor. Paine contended that the establishment of global peace paralleled a process of global democratisation that would liberate the masses from their political and economic exploitation at the hands of a powerful few, whose interests converged in the prosecution of war.