Political decision-making about increasingly global conflicts is always influenced by non-governmental 'experts' and opinion-makers. Sources of relevant 'knowledge' might be based in social science research findings or on-the-ground experience. The various forms of evidence, and evaluating political, moral and ideological claims associated with state actions in the international arena, pose particular challenges for the public intellectual, who can be expected to apply reliable and consistent methods of analysis. Is the voice of the intellectual heard? Do intellectuals have a responsibility to speak out? Do they speak out enough? If not, why not?