A senior U.S. intelligence official on May 29, 2019 accused Russia of secretly conducting nuclear tests in violation of an international treaty and the country’s own moratorium on such tests.

But there’s no hard evidence of these alleged tests, one arms-control group pointed out.

“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,” Lt. Gen. Robert Ashley, Jr., director of the Defense Intelligence Agency, said at an event at the Hudson Institute in Washington, D.C.

“Russia has likely been secretly carrying out very low-yield nuclear tests to upgrade its nuclear arsenal,” The Wall Street Journal the same day reported.

But the Arms Control Association in Washington, D.C. for one is skeptical of Ashley’s claim. “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.”

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.

Ashley’s allegation is consistent with repeated attempts by Pres. Donald Trump, his administration and his allies in Congress to dismantle existing arms-control regimes by accusing Russia of violating them, thus justifying a U.S. withdrawal from the same regimes and clearing the way for a U.S. arms build-up.

The Trump administration echoed the administration of Pres. Barack Obama in accusing Russia of willfully violating the 1987 Intermediate Nuclear Forces treaty, an accusation Russia has denied. The White House in February 2019 announced the United States’ withdrawal from the treaty, which bans land-based, medium-range missiles in Europe.

Republicans in Congress likewise have accused Russia of taking advantage of the 1992 Open Skies Treaty, which allows Russia, the United States and other countries to fly camera-equipped surveillance planes over each other’s territory in order to verify adherence to arms-control accords.

Republicans described the Russian flights over the United States as “spying,” even though Russia strictly abided by the treaty’s terms. Despite Republican attacks on Open Skies, the United States in 2019 remains a party to the treaty.

There’s irony in Ashley accusing Russia of violating the 1996 Comprehensive Test Ban Treaty, which according to the Arms Control Association “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,” the association pointed out.

National Security Advisor John Bolton is a noted critic of the CTBT, having “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.”

Again, there’s no hard proof that Russia has violated the treaty. But that isn’t stopping Ashley from undermining the accord. Ashley claimed that Russia has “not affirmed the language of zero-yield,” which would guarantee no nuclear explosions in tests.

“But Russia has repeatedly affirmed publicly that they believe the treaty prohibits all nuclear test explosions,” the Arms Control Association explained.

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.

David Axe serves as Defense Editor of the National Interest. He is the author of the graphic novels  War Fix, War Is Boring and Machete Squad.