"[Arms Control Today] has become indispensable! I think it is the combination of the critical period we are in and the quality of the product. I found myself reading the May issue from cover to cover."

– Frank von Hippel
Co-Director of Program on Science and Global Security, Princeton University
June 1, 2018
Threshold Test Ban Treaty (TTBT)

The Threshold Test Ban Treaty (TTBT) between the United States and the Soviet Union establishes a nuclear threshold through the prohibition of nuclear tests that exceed 150 kilotons. The threshold prevents the testing of new or existing nuclear weapons that exceed the fractional-megaton range. The United States and Soviet Union are subject to verification provisions. These are conducted through hydrodynamic yield measurements, seismic monitoring, and on-site inspections.

Opened for Signature: 3 July 1974

Entry into force: 11 December 1990

Official Text: http://www.state.gov/t/isn/5204.htm#treaty

Status and Signatories: http://www.state.gov/t/isn/5204.htm#narrative

ACA Backgrounder: https://www.armscontrol.org/factsheets/Nuclear-Testing-and-Comprehensive-Test-Ban-Treaty-CTBT-Timeline