The proliferation of regional institutions and initiatives in Asia over the past decade is unmatched in any other region of the world. The authors in this collection explore the distinctive features of these institutions by comparing them for the first time to the experience of other regions; from the elaborate institution-building of Europe to the more modest regional projects of the Americas. It is an opportune moment for this reassessment, as the European regional model faces a sovereign debt crisis while Asian economies see more secure sources of growth from their immediate neighbors. Asia's regional institutions display a distinctive combination of decision rules, commitment devices, and membership practices, shaped by underlying features of the region, the dynamics of regional integration, and the availability of institutional substitutes. Within this context, the authors propose changes that will better sustain the prosperity and peace that have marked Asia in recent decades.