Chapter 1 summarizes the core arguments of the book and introduces the significance of the project both theoretically and practically. The chapter argues that scholars and practitioners too often focus on aid effectiveness, ignoring how choices regarding aid delivery mechanism are made to being with. The chapter then provides a brief historical look at foreign aid, demonstrating that the history of foreign aid is a history of fads and fashions. Finally, the chapter summarizes the core theoretical argument of the book, which is that commitment problems constrain the policy compromises reached by donors and recipients. If we want to know whether an aid delivery mechanism is likely to be sustained over the long term, we need to look at whether it induces credible commitments from both donor agencies and recipient governments.