Operation Allied Force had a decisive impact on Tony Blair's leadership of UK foreign policy. This article begins with Blair's famous Chicago speech of April 1999; his clearest statement of an apparently underlying moral purpose in international relations. It then contrasts the conventional wisdom that over Kosovo Blair was acting out of a sense of moral obligation (sharpened by recent British failings to act to prevent humanitarian disasters in the Balkans) with a revisionist account centring on the domestic political considerations impelling Blair into this particular foreign policy adventure. Blair drew three lessons from his involvement in Operation Allied Force: that media presentation was a crucial aspect of implementing a successful foreign policy strategy; that he had been too cautious between 1997 and 1999, partly as a result of being chained to the vagaries of public opinion; and that he could generate robust and worthy foreign and defence policies sitting with his close advisers on the sofa of his äóÖden' in Downing Street rather than working through traditional channels. The key argument in conclusion is that there was a Tony Blair before Iraq, one who was genuinely set on building a consensus around humanitarian intervention.