From Saturday's Washington Post, "U.S. Shifts Stance on Nuclear Treaty":

In a significant shift in U.S. policy, the Bush administration announced this week that it will oppose provisions for inspections and verification as part of an international treaty that would ban production of nuclear weapons materials.

For several years the United States and other nations have pursued the treaty, which would ban new production by any state of highly enriched uranium and plutonium for weapons. At an arms-control meeting this week in Geneva, the Bush administration told other nations it still supported a treaty, but not verification.

Administration officials, who have showed skepticism in the past about the effectiveness of international weapons inspections, said they made the decision after concluding that such a system would cost too much, would require overly intrusive inspections and would not guarantee compliance with the treaty. They declined, however, to explain in detail how they believed U.S. security would be harmed by creating a plan to monitor the treaty.

Arms-control specialists reacted negatively, saying the change in U.S. position will dramatically weaken any treaty and make it harder to prevent nuclear materials from falling into the hands of terrorists. The announcement, they said, also virtually kills a 10-year international effort to lure countries such as Pakistan, India and Israel into accepting some oversight of their nuclear production programs.

The announcement at the U.N.-sponsored Conference on Disarmament comes several months after President Bush declared it a top priority of his administration to prevent the production and trafficking in nuclear materials, and as the administration works to blunt criticism by Democrats and others that it has failed to work effectively with the United Nations and other international bodies on such vital global concerns.

"The president has said his priority is to block the spread of nuclear materials to rogue states and terrorists, and a verifiable ban on the production of such materials is an essential part of any such strategy," said Daryl Kimball, director of the Washington-based Arms Control Association. "Which is why it is so surprising and baffling that the administration is not supporting a meaningful treaty."

[. . .]

While declaring nonproliferation a priority, however, the administration has opposed other arms-control treaties that rely on inspection regimes.

In 2001, the administration opposed attempts to create an inspections regime for the Biological Weapons Convention. It has signed an arms-reduction deal with Russia that doesn't include new verification mechanisms, and in its first year in office, the administration pulled out of the Anti-Ballistic Missile Treaty.