This article explores the role of international development cooperation — or aid — in foreign policy and diplomacy. Based on his experience as a practitioner, Arjan de Haan makes the observation that the development debate, and in particular the search for effective aid, has neglected the political role of aid. Moreover, the high political symbolism that aid has obtained, particularly in the last decade, has received relatively little attention. A political perspective on aid is now rapidly becoming more important, especially because of the enhanced importance of global security in setting an aid agenda, and because the old ways of working are — or seem to be — challenged by the rise of China and other countries that were recently (and still are) recipients of aid. An understanding of the diverse political motives behind aid should inform the way that aid effectiveness is measured. The changing politics in which aid is embedded are illustrated with reference to the Netherlands, which used to have one of the most respected aid programmes because of its multilateral emphasis and ‘untying’ of aid, and because Dutch strategic interests have now been made one of the cornerstones of the Netherlands’ new policy. The article hypothesizes that reinforcing progressive principles around international development can be a supportive element of a strengthened diplomacy in the globalized world beyond 2010.