According to at least some of the voluminous literature on the subject, the National Environmental Policy Act (NEPA)¹ may be an excellent example of effective environmental legislation, but it suffers from one serious limitation: the lack of a "substantive mandate."² These commentators argue that NEPA falls short of its potential, and perhaps its goals, because it fails explicitly to impose upon federal agencies a legally enforceable directive to enhance and refrain from degrading the environment. The absence of a single plaintiff's victory in a "substantive NEPA case"³ is accentuated by the extraordinary success record of those challenging agency noncompliance with the law's procedural dictates, specifically with respect to the preparation of environmental impact statements (EISs).

Although NEPA could have been drafted to pack more of a substantive punch,⁴ the contrast between its procedural strength and its substantive weakness is more interesting as an academic issue than important as a practical matter. This is demonstrated by a series of court decisions in which judges have avoided the harsh and often elusive distinction between the Act's substantive and procedural requirements and instead have instituted a thoughtful application of traditional principles of judicial review against a backdrop of the nation's environmental policies. Nevertheless, the notion that a chasm runs through the statute is firmly rooted.