This essay presents an argument for policies responsive to global environmental needs by examining the causes and consequences of six critical environmental issues, and then offering specific U.S. policy recommendations. Following an explanation of the global nature of environmental problems, a summary of the salient facts regarding the following six issues is provided: quality of the atmosphere, depletion of fresh water, loss of soil productivity, loss of genetic diversity, tropical deforestation, and toxic contamination and hazardous materials. In each of these cases, human behavior has disrupted the natural biogeochemical cycles of the biosphere, thereby generating chain reactions that multiply the problems confronting people and their governments. It is argued that regardless of the policy positions of the government on international environmental issues, U.S. citizens are involved in all of the aforementioned global issues and many more. The essay urges the United States to return to a position of leadership in global environmental matters, based on the conclusion that the cost of regaining credibility and leadership in international environmental affairs could be much less than the ultimate failure to do so. A glossary of acronyms and a list of Stanley Foundation papers and activities are also included in the document. (LH)