Advances in Monitoring Nuclear Weapon Testing

As this article goes to press, Iran’s nuclear program is rapidly expanding its capacity to enrich uranium. The terrorist attacks in Mumbai, India, last November have once more raised the specter of a nuclear weapons exchange between India and Pakistan—a “regional war” that could kill tens of millions of both countries’ citizens and lead to severe change in global climate. North Korea, having joined the nuclear club with its first successful explosive test of a fission weapon on October 9, 2006, has reportedly separated enough weapons-grade uranium to build at least half a dozen atomic bombs. Eight countries have openly tested nuclear weapons, and Israel is presumed to have them as well. The possibility that terrorists could get their hands on such weapons is the worst nightmare of the U.S. Department of Homeland Security and its counterparts around the world.

Yet there are hopeful signs for reducing nuclear tensions as well. By the end of 2008, 180 countries had signed the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which forbids all nuclear explosions, including the explosive testing of nuclear weapons. That treaty, adopted by the United Nations General Assembly in September 1996 and promptly signed by President Bill Clinton and many other world leaders, aims to restrict the further development of nuclear weapons by countries that have them and to prevent countries that do not possess them from building them with any confidence that the devices will work on the battlefield.

Even though the CTBT has not yet come into force, every nation that signed it—including the U.S. and Russia—has maintained a moratorium on nuclear weapons testing at least since the U.N. voted to adopt it. (The three nations that have tested nuclear weapons since 1996—India, North Korea and Pakistan—have not signed the treaty. In the U.S. this moratorium on testing has continued despite serious opposition to the treaty itself. In 1999 the U.S. Senate declined to give its constitutional “advice and consent” to the ratification of the agreement, and soon after t