Regulation is the most direct and predictable mechanism for controlling environmental behavior. Strong compliance and enforcement programs that punish violators and deter violations by others are, of course, essential to any successful regulatory system. It is increasingly clear, though, that regulation cannot by itself produce the behavioral changes needed to achieve sustainable environmental outcomes. The nature of environmental challenges has undergone such a fundamental change that the existing regulatory-focused system of environmental governance will not be able by itself to ensure healthy air, clean water, a stable climate, safe drinking water, vital ecosystems, and continuing biodiversity. Rather, environmental sustainability will require that the regulatory system be supplemented and supported through better alignment of economic drivers with environmental goals and by changes in societal values. Enforcement officials must play a significant part in this effort by both better understanding what motivates environmental behavior and how these motivations can be leveraged through the compliance and enforcement process to produce environmental gains, as well as to prevent environmental losses.