List of parties to the Comprehensive Nuclear-Test-Ban Treaty

The following 9 states have signed but not ratified the treaty.

Notes

The following 9 UN member states, in addition to the UN observer State of Palestine, have neither signed nor acceded to the treaty.

India

In 1998, India said it would only sign the treaty if the United States presented a schedule for eliminating its nuclear stockpile, a condition the United States rejected.

Israel

In 2016, Israeli Prime Minister Benjamin Netanyahu said that its ratification was dependent upon "the regional context and the appropriate timing".

United States

The United States has signed the CTBT, but not ratified it; there is ongoing debate whether to ratify the CTBT.

The United States has stated that its ratification of the CTBT is conditional upon:

A: The conduct of a Science Based Stockpile Stewardship Program to ensure a high level of confidence in the safety and reliability of nuclear weapons in the active stockpile, including the conduct of a broad range of effective and continuing experimental programs.

B: The maintenance of modern nuclear laboratory facilities and programs in theoretical and exploratory nuclear technology which will attract, retain, and ensure the continued application of our human scientific resources to those programs on which continued progress in nuclear technology depends.

C: The maintenance of the basic capability to resume nuclear test activities prohibited by the CTBT should the United States cease to be bound to adhere to this treaty.

D: Continuation of a comprehensive research and development program to improve our treaty monitoring capabilities and operations.

E: The continuing development of a broad range of intelligence gathering and analytical capabilities and operations to ensure accurate and comprehensive information on worldwide nuclear arsenals, nuclear weapons development programs, and related nuclear programs.

F: The understanding that if the President of the United States is informed by the Secretary of Defense and the Secretary of Energy (DOE) – advised by the Nuclear Weapons Council, the Directors of DOE's nuclear weapons laboratories and the Commander of the U.S. Strategic Command – that a high level of confidence in the safety or reliability of a nuclear weapon type which the two Secretaries consider to be critical to the U.S. nuclear deterrent could no longer be certified, the President, in consultation with Congress, would be prepared to withdraw from the CTBT under the standard "supreme national interests" clause in order to conduct whatever testing might be required.

Proponents of ratification claim that it would:

1. Establish an international norm that would push other nuclear-capable countries like North Korea, Pakistan, and India to sign.
2. Constrain worldwide nuclear proliferation by vastly limiting a country's ability to make nuclear advancements that only testing can ensure.
3. Not compromise US national security because the Science Based Stockpile Stewardship Program serves as a means for maintaining current US nuclear capabilities without physical detonation.

Opponents of ratification claim that:

1. The treaty is unverifiable and that other nations could easily cheat.
2. The ability to enforce the treaty was dubious.
3. The U.S. nuclear stockpile would not be as safe or reliable in the absence of testing.
4. The benefit to nuclear nonproliferation was minimal.

On October 13, 1999, the United States Senate rejected ratification of the CTBT. During his 2008 presidential election campaign Barack Obama said that "As president, I will reach out to the Senate to secure the ratification of the CTBT at the earliest practical date." In his speech in Prague on April 5, 2009, he announced that "[To] achieve a global ban on nuclear testing, my administration will immediately and aggressively pursue U.S. ratification of the Comprehensive Test Ban Treaty. After more than five decades of talks, it is time for the testing of nuclear weapons to finally be banned."

An article in Bulletin of the Atomic Scientists describes how a North Korean underground nuclear test on May 25, 2009, was detected and the source located by GPS satellites. The authors suggest that the effectiveness of GPS satellites for detecting nuclear explosions enhances the ability to verify compliance with the Comprehensive Nuclear Test Ban Treaty, giving the United States more reason to ratify it.

• List of parties to the Biological Weapons Convention
• List of parties to the Chemical Weapons Convention
• List of parties to the Convention on Certain Conventional Weapons
• List of parties to the Ottawa Treaty
• List of parties to the Partial Nuclear Test Ban Treaty
• List of parties to the Treaty on the Non-Proliferation of Nuclear Weapons
• List of parties to the Treaty on the Prohibition of Nuclear Weapons
• List of parties to weapons of mass destruction treaties

• Depository website with info on signatures and ratifications
• Country Profiles on the CTBTO Preparatory Commission Website