Economic success breeds other issues, however. One of the most vexing concerns facing the American public today is growth. Economic growth has been central to America's success. As the economic pie has grown, new generations have had a chance to carve a slice for themselves. Indeed, economic growth and the opportunities it brings have helped keep class friction in the United States at a minimum. But is there a limit to how much growth can -- and should -- be sustained? In many communities across America, citizens' groups find themselves resisting proposed land developments for fear their quality of life will deteriorate. Is growth worthwhile, they ask, if it brings overcrowded highways, air pollution, and overburdened schools? How much pollution is tolerable? How much open space must be sacrificed in the drive to create new jobs? Similar concerns occur on the global level. How can nations deal with environmental challenges such as climate change, ozone depletion, deforestation, and marine pollution? Will countries be able to constrain coal-burning power plants and gasoline-powered automobiles enough to limit emissions of carbon dioxide and other greenhouse gases that are believed to cause global warming? Because of the huge size of its economy, the United States necessarily will be a major actor in such matters. But its affluence also complicates its role. What right does the United States, which has achieved a high standard of living, have to demand that other countries join in efforts to take actions that might constrain growth in order to protect the environment? There are no easy answers. But to the extent that America and other nations meet their fundamental economic challenges, these questions will become increasingly important. They remind us that while a strong economy may be a prerequisite to social progress, it is not the ultimate goal. 111