The Treaty on the Non-Proliferation of Nuclear Weapons (also known as the Nuclear Non-Proliferation Treaty, or NPT) is an international agreement designed to prevent the spread of nuclear weapons, promote cooperation between states on peaceful uses of nuclear energy, and advance nuclear disarmament. The NPT was opened for signature on July 1, 1968, and the […]
Fact Sheet: The Comprehensive Test Ban Treaty (CTBT)
Updated January 2025 The Comprehensive Test Ban Treaty (CTBT) is a multilateral agreement that prohibits the explosive testing of nuclear weapons. The CTBT opened for signatures on September 24, 1996, but the agreement is still in the ratification stage. The United States has signed, but has not yet ratified the treaty. The United States conducted […]
Fact Sheet: Intermediate-Range Nuclear Forces (INF) Treaty
Updated May 2025 The Intermediate-Range Nuclear Forces Treaty (INF, or The Treaty Between the United States of America and the Union of Soviet Socialist Republics on the Elimination of Intermediate-Range and Shorter-Range Missiles) was signed on December 8, 1987, and entered into force on June 1, 1988. The treaty required parties to eliminate nuclear and […]
Why New START Matters
By Bernadette Stadler and Helen Thompson Recent media reports that President Donald Trump denounced the New Strategic Arms Reduction Treaty (New START) in his first phone call with Russian President Vladimir Putin have caused major concern within the nonproliferation community. When Mr. Putin raised the possibility of extending the treaty, which expires in 2018, President Trump reportedly […]
Fact Sheet: The Treaty on Open Skies
Updated June 2021 The Treaty on Open Skies allows for states party to the treaty to conduct unarmed observation flights over the territory of other states to foster inter-military transparency and cooperation. The United States, Canada, and 22 European countries including Russia signed the treaty in Helsinki on March 24, 1992. The United States Senate […]
