In prepared remarks delivered Wednesday at a Hudson Institute event, Lt. Gen. Robert P. Ashley, Jr., the director of the Defense Intelligence Agency, stated that “The United States believes that Russia probably is not adhering to its nuclear testing moratorium in a manner consistent with the ‘zero-yield’ standard” outlined in the 1996 Comprehensive Test Ban Treaty (CTBT).
Any violation of the CTBT by Russia, which has signed and ratified the agreement, would be a serious matter. But when pressed on the allegation in the question and answer session of the event by Wall Street Journal reporter Michael Gordon, Ashley would only say that Russia had the “capability” to conduct very low-yield supercritical nuclear tests in contravention of the treaty, a capability which Russia, China, and the United States have long had. He did not say that Russia has conducted or is conducting such tests.
The CTBT prohibits any nuclear test explosions that produce a self-sustaining, supercritical chain reaction and creates a robust international verification regime.
The United States has signed but not ratified the treaty.
Critics of the CTBT and arms control more broadly, including National Security Advisor John Bolton, have long claimed that the treaty does not adequately define a nuclear test, that Russia and China have a different interpretation than the United States of what the treaty prohibits, and that Moscow and Beijing have conducted nuclear tests in violation of the treaty.
But no public evidence has ever been provided to support the claim of illegal Russian testing and Gen. Ashley didn’t provide any Wednesday. Former Undersecretary of States for Arms Control and International Security Rose Gottemoeller told the House Armed Services Committee in December 2015 that “within this century, the only state that has tested nuclear weapons … in a way that produced a nuclear yield is North Korea.” This begs the question of what, if anything, has changed since then that would support a different conclusion.
Gen. Ashley also claimed that Russia has “not affirmed the language of zero-yield.” But Russia has repeatedly affirmed publicly that they believe the treaty prohibits all nuclear test explosions. For example, Russian Deputy Foreign Minister Sergey Ryabkov noted in a 2017 op-ed that the treaty “prohibits ‘any nuclear weapon test explosion or any other nuclear explosion,’ anywhere on Earth, whatever the yield.”
The most effective way for the United States to enforce compliance with the zero-yield standard is for the Trump administration and the U.S. Senate to support ratification of the treaty and help to bring it into force, which would allow for intrusive, short-notice, on-site inspections to detect and deter any possible cheating. In the meantime, if the U.S. has credible evidence that Russia is violating its CTBT commitments, it should propose, as allowed for in Articles V and VI of the treaty, mutual confidence building visits to the respective U.S. and Russian test sites by technical experts to address concerns about compliance.