This article examines the evolution and application of sustainability concepts in environmental politics and policy, paying particular attention to the challenges of operationalizing and measuring sustainability in the highly dynamic environment of twenty-first-century politics and policy. It first surveys the concept\u27s historical roots, and then examines the struggle to refine and apply the concept in contemporary policy analysis. It reviews the key policy initiatives that have incorporated sustainability language or contributed to its development within each branch of government. It then focuses on the pragmatic adoption of sustainability principles in policy making, culminating in a discussion of future directions and research needs.h...