Today, a growing number of states are looking to nuclear power to meet their future energy needs. The technologies involved are also capable of use for military purposes. Hence the global concern to limit the spread of nuclear weapons without, at the same time, impeding the development of peaceful applications of nuclear power. The Parker Report concerning the application by British Nuclear Fuels Ltd to build a reprocessing plant at Windscale highlights the problems, legal, political and moral, that attempts to reconcile these twin aims give rise to. This article, after analysing the Report's treatment of the non-proliferation question, considers the wider international legal implications of the decision to permit the building of the plant, with particular reference to the Non-Proliferation Treaty and the anti-proliferation policies of the Carter Administration in the United States.