The pages of history are filled with stories of important and worthy international efforts that took years to triumph, and suffered many setbacks along the way. Some said the superpowers would never limit their nuclear arsenals-but they did. Some said we would never rid the world of smallpox; that we would never join together to take action to fix the ozone hole in the atmosphere. But we did.
Likewise, I am confident that world efforts to fight global warming will continue. I am equally confident that the United States will continue to be a leader in this fight. We will not give up. The stakes are too high; the science too decisive; and our planet and our children too precious. Frank E. Loy, Under Secretary for Global Affairs and Head of the US Delegation to the COP6 negotiations, speaking after the negotiations held in The Hague collapsed on November 25, 2000.
There is a joke—told, I think, by President Ronald Reagan—that the economist, having seen something work in practice, tries to show how it could be made to work in theory. It might be argued that this is all that I have done in this book, but I hope that I have shown much more.
I began this book by demonstrating that it is not even obvious how to tell whether a particular agreement really “works.” I have presented a theory capable of explaining why the more obvious successes of international cooperation have worked—and in the course of doing so I have also explained why other treaties have failed. The theory is simplistic but it also makes sharp predictions.
It shows, for example, that there is not a magic formula for success, and that different environmental problems must be approached in different ways. It also shows that enforcement is critical. It cautions against the view that countries can solve the enforcement problem simply by appealing to a state's responsibilities, by exhortation, by naming and shaming, and by offering assistance. These measures may be helpful; and, diplomatically, they may be necessary; but they will not suffice for remedying the hardest cooperation failures. To address these, countries must be able to make credible threats both to deter free-riding and to enforce compliance. The problem is that the threats needed to sustain full cooperation will not always be credible. In hurting the countries that fail to cooperate, the countries seeking to enforce an agreement typically injure themselves—and this is an outcome they would rather avoid. If there is one aspect of my approach that distinguishes it from the rest of the