"No one can solve this problem alone, but together we can change things for the better." 

– Setsuko Thurlow
Hiroshima Survivor
June 6, 2016
Reconsidering the Test Ban Treaty

November 2015

By Daryl G. Kimball

Two decades ago, on August 11, 1995, President Bill Clinton announced the United States would seek the negotiation of a true, zero-yield global nuclear test ban treaty, thereby ending the practice of using nuclear weapons detonations to proof-test new designs. 

Clinton also directed the Energy Department and the nuclear weapons laboratories to embark on an ambitious and, at the time, unproven science-based stockpile stewardship strategy using surveillance, experimental modeling, and refurbishment to maintain the existing arsenal. 

The decisions opened the way for the conclusion of negotiations on the Comprehensive Test Ban Treaty (CTBT) in 1996. The treaty has effectively halted nuclear explosive testing worldwide (only North Korea has conducted nuclear tests since 1998) and slowed the global arms race. The International Monitoring System (IMS) established by the treaty to verify compliance is operational. With 183 state signatories, the treaty is now a centerpiece of the international nuclear nonproliferation system.

But the door to the resumption of nuclear testing remains open, largely because of the U.S. Senate’s highly partisan and rushed vote to reject ratification of the treaty in 1999 and the United States’ failure to reconsider the treaty in the 16 years since. U.S. inaction has, in turn, given the leaders of the seven other states that must ratify the CTBT for its entry into force an excuse for delay.

At an event last month commemorating Clinton’s 1995 actions, Energy Secretary Ernest Moniz and Secretary of State John Kerry suggested that the Senate should re-examine the CTBT in light of the proven success of the Stockpile Stewardship Program and the advances in the IMS to verify compliance with the treaty.

“The factors that led some senators to oppose the treaty in 1999 have changed, and so, choices should change as well,” Kerry said.

At the event, the directors of the three U.S. nuclear weapons labs each provided their strongest public affirmation to date that the stewardship effort has been “a success” in “sustaining high confidence in the stockpile.” As Moniz put it, “[E]very science-based stockpile tool that had been planned [is] delivering results and, in many cases, well beyond the original expectations.”

Kerry noted that the IMS, which was still under construction in 1999 and is now 90 percent complete, is providing real-time data around the clock to detect and deter clandestine nuclear tests. In 2012 a National Academy of Sciences panel found that the IMS, national technical means of intelligence, and civilian seismic networks are now so powerful that no potential CTBT violator could be confident that a nuclear explosion of military utility would escape detection.

Kerry said he was “determined that, in the months to come, we’re going to reopen and re-energize the conversation about the treaty on Capitol Hill and throughout our nation.”

Such an effort is welcome and long overdue, but it cannot be done hastily. Bringing the CTBT back to the Senate for another vote requires a lengthy, intensive educational and outreach campaign to present the new information, answer detailed questions, and dispel old myths and misconceptions. To date, President Barack Obama has not devoted the effort necessary to ultimately achieve CTBT ratification, and in his short time left in office, he cannot win enough support for the treaty in this Republican-led Senate.

Yet, the renewed focus on the CTBT at this time is crucial because the treaty still matters for U.S. and international security in the 21st century. 

As Siegfried Hecker, the former director of Los Alamos National Laboratory, has written, the main reason is that “it is critical to erect as many barriers as possible to the resumption of testing. Ratification of the CTBT and its entry into force is the most important such barrier.”

With the CTBT in place, the United States can reduce the likelihood of successful, clandestine nuclear explosive testing and inhibit the development of new types of strategic nuclear weapons by other countries. 

The test ban would make it far more difficult for nuclear-armed states, including China, India, and Pakistan, to perfect the more compact warhead designs that would allow them to field missiles armed with multiple warheads. It also would add another impediment for states such as Iran that might consider the nuclear weapons option in the future.

U.S. action on the CTBT would prompt other holdouts, such as China, India, Israel, and Pakistan, to consider ratifying the treaty. Even with possible U.S. reconsideration and ratification of the CTBT in 2017 or 2018, entry into force is still years away.

In the meantime, it is essential that U.S. leaders seek and support ways, including actions by the UN Security Council, to reinforce the de facto global nuclear testing moratorium and make it clear that further nuclear testing would be a threat to international peace and security.

Two decades after the decision to permanently forgo nuclear explosive testing, the United States is still not reaping the security benefits that would come with CTBT ratification. The Obama administration is right to invite senators to reconsider the CTBT. Before rushing to judgment, senators should carefully consider the new information and analysis of the issues surrounding this longest-sought, hardest-fought nonproliferation goal.