This essay seeks to lay the foundation for an understanding of welfare state retrenchment. Pre vious discussions have generally relied, at least implicitly, on a reflexive application of theories designed to explain welfare state expansion. Such an application of "logic of industrialism," "power resources," and "new institutionalist" arguments is seriously flawed. Not only is the goal of retrenchment (avoiding blame for cutting existing programs) far different from the goal of expansion (claiming credit for new social benefits), but the welfare state itself vastly alters the terrain on which the politics of new social policy is fought out. Only an appreciation of how ma ture social programs create a "new politics" can allow us to make sense of the welfare state's re markable resilience over the past two decades of austerity. Theoretical argument is combined with quantitative and qualitative data from four cases (Britain, the United States, Germany, and Sweden) to demonstrate the shortcomings of conventional wisdom and to highlight the factors that limit or facilitate retrenchment success.Earlier versions of this paper were presented at the Conference of Euro})ellnists, Chicago, March 1994, and the American Political Science Association Meetings, New York, September 1994. Miguel Glatzer provided considerable research assistance as well as helpful comments.