A top U.S. military official has said that U.S. intelligence agencies believe Russia is likely conducting low-yield nuclear testing that may be violation of a major international treaty.
Lieutenant General Robert Ashley said in a speech on May 29 that Russia could be doing tests that go "beyond what is believed necessary, beyond zero yield."
The problem, he said, was that Russia "has not been willing to affirm" they are adhering to the 1996 Comprehensive Nuclear Test Ban Treaty.
"The United States believes that Russia probably is not adhering to its nuclear testing moratorium in a manner consistent with the 'zero-yield' standard," said Ashley, who is director of the Defense Intelligence Agency, the Defense Department's main in-house intelligence organization.
"Zero-yield" refers to a nuclear test where there is no explosive chain reaction of the sort caused by an atomic bomb nuclear warhead.
Asked specifically whether U.S. intelligence agencies had concluded Russia was conducting such tests in violation of the treaty, Ashley said, "They've not affirmed the language of zero yield."
"We believe they have the capability to do it, the way that they're set up," Ashley said during an appearance at the Hudson Institute, a Washington, D.C., think tank.
The Comprehensive Nuclear Test Ban Treaty bans all nuclear explosions, either military or civilian, in any type of situation. It’s been signed and ratified by Russia, and signed by the United States, but not ratified.
There was no immediate comment by the Kremlin or the Russian Defense Ministry about the conclusions, which were first reported on May 29 by The Wall Street Journal.
But Vladimir Shamanov, chairman of the defense committee in Russia's lower house of parliament, called Ashley's statement "irresponsible."
"It would be impossible to make a more irresponsible statement," Interfax quoted Shamanov as saying.
"These kinds of statements reveal that the professionalism of the military is systemically falling in America," said Shamanov, a retired colonel general and a former commander of Russia's Airborne Troops. "These words from a U.S. intelligence chief indicate that he is only an accidental person in this profession and he is in the wrong job."
The U.S. assertion comes with several major arms-control treaties under strain, largely due to the toxic state of relations between Washington and Moscow.
Earlier this year, President Donald Trump's administration announced it was pulling out of the 1987 Intermediate-Range Nuclear Forces Treaty, an agreement that eliminated an entire class of missiles.
Another treaty, New START, is due to expire in 2021 unless the United States and Russia agree to extend it for five years.
The Arms Control Association, a Washington-based research and advocacy group, called for U.S. administration officials to release more evidence to back up the assertion, and for the Senate to ratify the Comprehensive Nuclear Test Ban Treaty.
"If the U.S. has credible evidence that Russia is violating its CTBT commitments, it should propose...mutual confidence-building visits to the respective U.S. and Russian test sites by technical experts to address concerns about compliance," the group said.