The U.S. Senate's rejection of the CTBT in October 1999 does not free the United States from the Treaty's norm against nuclear-weapon test explosions. Nor does it mean that the Senate will never approve the Treaty. But it does mean that the final U.S. position on the Treaty almost certainly will not be known until after the next U.S. presidential election in November 2000. Moreover, a debate to build domestic and international support for U.S. adherence to the Treaty's norm could help to produce eventual Senate approval.