This paper reviews the battles over the Forest Service planning rule that culminated in the November 2000 revising of the regulations implementing the National Forest Management Act. In a departure from the agency's emphasis on multiple use, the rule established ecological sustainability as the key objective guiding planning for the national forests. The supporting material explicitly states that "it is based on the recommendation of an eminent committee of scientists." This paper examines the Committee of Scientists and the NFMA rule as a case study in the relation between science and politics in the development and implementation of statutory standards for management of the National Forest System. The conclusion considerations the broader question of whether the Committee and Forest Service overstepped their appropriate roles in promoting what is essentially a new statutory mandate.