This article addresses the question of how unexpected national and international emergencies - the 'black swans' of war, economic depression, hyperinflation and, more prospectively and topically, terrorist incidents and environmental catastrophes - affect the character of welfare state interventions and welfare state development. We do have clear evidence of such effects in the past: hyperinflation in Germany made that country particularly inflation averse; the Great Depression was a stimulus to welfare state development in countries such as Sweden and New Zealand; and the Second World War was a key factor in the subsequent development of the post-war British welfare state. However, the impact of emergencies is, at best, a very minor theme of welfare state analysis and one largely left to historians of the welfare state, suggesting that such effects are no longer considered to be a major factor shaping welfare state development and that welfare states are like 'elephants on the move', rarely significantly thrown off course by particular events. The article speculates on why that might be, noting the importance of the timing of the emergency, its type, size, and the extent and character of prior welfare provisions. The article concludes by examining the implications of this analysis for our understanding of the likely impact of possible future emergencies of a terrorist or environmental character and of the proper political response to such emergencies.