This paper reports the implications of the current state of the art on the science of strategic behavior for the national treatment of different kinds of international environmental public good. While many environmental public goods are managed through multilateral environmental agreements aimed at building consensus over time (social norms), others are not. Many of the regulating and supporting services identified by the Millennium Ecosystem Assessment, for example, are not subject to agreement. The provision of these ecosystem services depends on the independent actions of many countries. For such environmental public goods it is important to have answers to these questions: Is it necessary to cooperate or coordinate with other countries in their provision? Will unilateral action provide a good-enough outcome? When can individual countries or small coalitions of countries enhance provision of environmental public goods? To answer such questions it is necessary to understand the nature of the environmental public goods, the socio-economic conditions in which they are provided, and the strategic interactions involved. With such an understanding, it is possible to estimate the likelihood that independent voluntary action may produce a 'good enough' outcome.