"In my home there are few publications that we actually get hard copies of, but [Arms Control Today] is one and it's the only one my husband and I fight over who gets to read it first."

– Suzanne DiMaggio
Senior Fellow, Carnegie Endowment for International Peace
April 15, 2019
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