The Review and Extension Conference of the Non-Proliferation Treaty (NPT) will convene in 1995. The primary issue to be considered at the Extension Conference is whether the NPT, universally regarded as the most important bulwark against the spread of nuclear weaponry, should remain in force. In this article, David A. Koplow argues that the United States must negotiate a Comprehensive Test Ban Treaty (CTBT) in order to maintain the non-proliferation regime and promote its own long-run security interest