ABSTRACT This paper addresses the question posed in its title. The absence of a third generation environmental law in the form of an interstate convention dealing with tropical and temperate deforestation, and mandating sustainable forestry practices, is not the result of a lack of effort. Rather, it is, I argue, inherent in the political economy and history of national forestry programs. These were originally devised to conserve timber through managed production, with little attention being paid to the other environmental services provided by forests. As a result, very strong domestic interests developed with great concern for continuing logging and little concern about the environment. It is this legacy, very different from that characterizing other commons issues, that obstructs progress on a global forest convention. In lieu of such an agreement, there are a growing number of groups, organizations and companies offering various forms of environmental certification to timber companies. These are meant to operate through the market for timber products, on the assumption that environmentally-concerned consumers will choose the greener product. Eventually, goes the argument, the profit motive will move timber producers to be green and to manage their forests in a sustainable fashion. For the time being, this must be considered a hope rather than an outcome. In 1992, representatives of 180 of the world's nations met in Rio de Janeiro to consider, among other things, the adoption of an Agreement on Forestry Principles, entitled a Non-legally binding authoritative statement of principles for a global consensus on the management, conservation and sustainable development of all types of forests.(1) The statement was the result of several years of sustained, intensive negotiation and controversy, a product of growing concern during the 1980s and early 1990s about the future of the world's remaining tropical forests. That this meeting was taking place in Brazil was especially apposite for two reasons. First, the burning forests of Amazonia had, during the late 1980s, served to focus global attention on their survival as well as their role in the global environment. Second, the Brazilian government expressed strong opposition to any hint of internationalization of its sovereign resources and territory (for background, see, e.g., Goodman & Hall, 1990; Schmink and Wood, 1992). Opposition to the statement was, however, much broader than support, and the Forestry Principles crashed and burned. During the intervening years, there have been continuing efforts to resurrect some version of the principles in the form of an International Forest Convention but, so far, these have been for naught. In this paper, I investigate the reasons for, and responses to, this failure. It is worth noting that the title of this paper is somewhat misleading. Instead of the question posed there, we should ask, Why is there no global forestry convention of the type we find in several other environmental issue areas, such as ozone, toxics and biodiversity? For the fact is that there do exist several forms of international forestry regulation, although they are, for the most part, deeply embedded within long-standing national legal and regulatory systems. If we examine national forest regimes, as I do briefly in this paper, we will discover that virtually all contemporary forest management systems have been derived from principles and practices developed originally in what would eventually become Germany, subsequently revised and adopted by France, Britain and the United States and later diffused throughout European colonial territories (Scott, 1998; see also Schama, 1995; Peluso, 1992). In all instances, these systems of practice were implemented as representing the best available approach to forest management at the time. Inasmuch as these management techniques were intended by state authorities not for purposes of forest preservation, but rather, conservation and commodification, it is not surprising that a global forestry convention has proven so difficult to formulate. …