Setting the Political Stage

Abstract

Calls for the cessation of nuclear testing can be traced back to the beginning of the nuclear age. Over the years a number of attempts to negotiate an end to testing failed, usually because of an inability to agree on verification provisions, in particular on-site inspections. However, in 1963, the United States, United Kingdom, and Soviet Union negotiated the Treaty Banning Nuclear Weapon Tests in the Atmosphere, Outer Space and Under Water, known as the Partial Test Ban Treaty (PTBT), a precursor to the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Because underground testing was excluded from the ban, onsite inspections were not called for. However, the PTBT did include in its Preamble and Article I a commitment to negotiate “the permanent banning of all nuclear test explosions” (PTBT 1963). In 1974 the United States and the Soviet Union signed the Threshold Test Ban Treaty (TTBT), which prohibited tests having a yield exceeding a threshold of 150 kilotons (equivalent to 150,000 tons of TNT). Although the treaty did not enter into force until the two countries completed a verification protocol in 1990, both parties to the TTBT also undertook an obligation in the Preamble and Article I to continue negotiations toward the cessation of all underground nuclear weapon tests (TTBT 1974/1990).