LAWS AND TREATIES are two powerful tools that nations throughout the world use to try to provide legal protection for endangered and threatened species. Unfortunately, though well intentioned, these efforts have sometimes fallen short of their goal.

The Endangered Species Act

The Endangered Species Act (ESA) was passed by the U.S. Congress and signed into law by President Richard M. Nixon on December 28, 1973. This comprehensive law provided legal protection for endangered species and gave the federal government broad powers to prevent the destruction of species and their habitat.

The ESA established three categories to describe the status of a given species: endangered, threatened, and stable.

A species is classified as endangered when it is in imminent danger of extinction throughout all or a significant portion of its range (the area in which it lives). A species is...