It is one thing -- but no less a bad thing -- for U.S. President George W. Bush to turn his back on pledges to protect the environment that he made during last year's campaign. It is quite another for him to do so in a manner that upsets U.S. allies and undermines his credibility. His abrupt decision to reject the 1997 Kyoto treaty on global warming does just that.

The president encountered a firestorm of criticism when he announced last week that he considers the global warming agreement to be dead. "The president has been unequivocal. He does not support the Kyoto treaty," said his official spokesman, Mr. Ari Fleischer. "It is not in the United States' economic best interest." The head of the Environment Protection Agency, Ms. Christine Todd Whitman, drove the point home: "We have no interest in implementing that treaty."

They are half-right. The U.S., along with other countries, has concerns about the particulars of the Kyoto agreement. The strict implementation of its provisions would require wrenching adjustments in the U.S. economy at a time when it, and the world, can least afford them. The treaty does impose more stringent requirements on developed nations, such as the U.S., but they are the biggest greenhouse-gas polluters. The U.S. has only 6 percent of the world's population, but accounts for roughly 25 percent of world carbon-dioxide emissions. Moreover, the Senate had made it clear -- in a 95-0 vote prior to the final 1997 agreement -- that it would not support a pact that did not bind both developing and developed countries. As Mr. Fleischer said, the treaty had never come into force, so "there's nothing to withdraw from."