This chapter examines the roles of compliance and deterrence strategies of environmental enforcement, arguing that neither is likely to be successful except in particular circumstances. It goes on to suggest that better results will be achieved by developing more sophisticated strategies which employ a judicious blend of persuasion and coercion, with the mix being adjusted to the particular circumstances and motivations of the entity that regulators are dealing with. This is the enterprise of ‘responsive regulation’, upon which a further strategy, ‘smart regulation’, builds. Under the latter, public agencies may harness institutions and resources residing outside the public sector (in conjunction with a broader range of complementary policy instruments) to further policy objectives. While there are no ‘magic bullets’ and no single approach that will function effectively and efficiently in relation to all types of enterprises and all circumstances, some approaches are considerably better than others, and there is much to be learnt from each of the regulatory models described above.