Michael Walzer’s use of John Stuart Mill’s A Few Words on Non-Intervention (1859) helped to inaugurate it as a canonical text of international theory. However, Walzer’s use of the text was highly selective because he viewed the first half as a historically parochial discussion of British foreign policy, and his interest in the second was restricted to the passages in which Mill proposes principles of international morality to govern foreign military interventions to protect third parties. As a result, theorists tend (...) to see those canonized passages as if through a glass darkly. Attention to the detail and context of Mill’s first-half critique of Lord Palmerston’s opposition to the Suez Canal project reveals that his discussion of purely protective intervention is embedded in a broader exploration of the limits of self-defence, including the moral permissibility of preventive military force and the use of protective interventions for defensive purposes. Moreover, reading the text holistically facilitates a refutation of some objections directed at it by Michael Doyle to the effect that Mill’s conception of self-defence incorporates elements of aggression which makes it extremely dangerous when adapted for application to the contemporary world. (shrink)