A deadly accident in northern Russia earlier this month caused the U.S. arms control community to stand up and take notice. The Russians claim they were testing “isotopic sources of fuel on a liquid propulsion unit,” and that only after the test was completed did the engine explode. There was a spike in radiation levels detected in the city of Severodvinsk, roughly 18 miles away, shortly after the accident. Seven people were killed as a result of the explosion, including at least two who died of acute radiation poisoning. Scores of others were exposed to radioactive materials, and subsequently decontaminated and placed under observation. Within days, the Russians declared that all radiation readings in and around the accident site were at normal levels.

Many Western experts believe that the Russians were testing a nuclear-powered cruise missile, the 9M730 “Burevestnik”—known in the West by its NATO designation, the SSC-X-9 “Skyfall”—and that a miniature nuclear reactor these experts believe was used to power the missile exploded. Other experts, including me, question this conclusion. But a recent report by Roshydromet, the Russian agency responsible for sampling air quality, showed the presence of four distinct isoptopes in the atmosphere after the accident that are uniquely sourced to the fission of uranium 235, strongly suggesting that a reactor of some sort was, in fact, involved (mitigating against this conclusion is the fact that no iodine 131 was detected; iodine 131 is the most prevalent isotope produced by the fission of uranium 235, and its absence would be highly unlikely in the event of any reactor explosion).

The bottom line, however, is that no one outside the Russians responsible for the failed test know exactly what system was being tested, why it was being tested, how it was being tested, and why that test failed. The Russian government has refused to provide any details about the test. “When it comes to activities of a military nature,” Russian President Vladimir Putin said in a press conference a few days after the accident, “there are certain restrictions on access to information. This is work in the military field, work on promising weapons systems. We are not hiding this,” he said, adding, “We must think of our own security.”

Others were thinking about their own security as well.

“Something obviously has gone badly wrong here,” U.S. national security adviser John Bolton said after the accident. Bolton observed that Russia is seeking to “modernize their nuclear arsenal to build new kinds of delivery vehicles, hypersonic glide vehicles, hypersonic cruise missiles,” noting that “dealing with this capability … remains a real challenge for the United States and its allies.” The U.S. and Russia are currently discussing the extension of the New START treaty on strategic arms reduction, scheduled to expire in early 2021. “If there is going to be an extension of the New START,” U.S. Defense Secretary Mark Esper said, “then we need to make sure that we include all these new weapons that Russia is pursuing.”

But this is problematic—the new Russian weapons under development are directly linked to the decision by the George W. Bush administration in 2002 to withdraw from the Anti-Ballistic Missile (ABM) treaty, a 1972 agreement that limited the number and types of ABM weapons the U.S. and then-Soviet Union could deploy, thereby increasing the likelihood that any full-scale missile attack would succeed in reaching its target. By creating the inevitability of mutual nuclear annihilation (a practice referred to as “mutually assured destruction,” or MAD), both the U.S. and Soviet strategic nuclear forces served as a deterrent against one another.

The deployment by the U.S. of modern ABM systems in the aftermath of its withdrawal from the ABM treaty, Russia believes, threatens its strategic nuclear force and thereby nullifies its deterrent potential. From the Russian perspective, only by building a new generation of modern nuclear delivery systems specifically designed to defeat U.S. ABM capability can Russia reassert its strategic nuclear deterrent. “We have repeatedly told our American and European partners who are NATO members we will make the necessary efforts to neutralize the threats posed by the deployment of the US global missile defense system,” Putin stated during a 2018 speech. According to him, “Nobody really wanted to talk to us about the core of the problem, and nobody wanted to listen to us.” Putin unveiled Russia’s new nuclear arsenal—which included the Burevestnik missile—and stared into the camera, declaring, “So, listen to us now!”

Complicating matters further is the notion put forward by Esper that the weapons Putin unveiled in 2018 would require that the New START treaty be modified prior to any extension, impeding what otherwise would simply have been an automatic extension, based upon mutual consent, for a five-year period. The Russians took umbrage over this position. “If we want to really comprehend the core of the matter,” Vladimir Yermakov, Russia’s deputy foreign minister for nonproliferation and arms control, told the Russian press earlier this month, “it should be noted that the New START Treaty covers specific categories of strategic arms, including intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), heavy bombers and ICBM and SLBM launchers. The Treaty,” Yermakov emphasized, “does not cover any other weapons systems.” Regarding the failed test of Aug. 8, Yermakov declared: “This also concerns the relevant research and development projects.” Yermakov categorically rejected the proposition put forward by Esper, noting that “the question of hypothetically extending the New START Treaty with certain weapons systems that do not fit into the aforementioned categories is absolutely unacceptable.”

Esper’s position, Yermakov said, did not take the Russians by surprise. “As of late,” Yermakov said, “we have been hearing US officials express doubts more and more often as to whether extending the New START Treaty makes sense. It is hard to perceive this as anything other than a conscious effort to lay the required media groundwork and to invent pretexts for declining to extend the agreement after it expires in February 2021 and to obtain absolute freedom to build up the US nuclear arsenal, even to the detriment of strategic stability and international security.”

The Russian position on the extension of the New START treaty, Yermakov said, is that it would “be a reasonable and responsible step, making it possible to prevent a complete breakdown in the area of strategic stability,” and “would also provide extra time to consider joint approaches towards new weapons systems that are currently emerging and possible new arms control treaties.” But before any extension could be considered, the Russian side insisted that the U.S. resolve an outstanding issue of treaty compliance that centered around 56 Trident SLBM launchers and 41 B-52H bombers that were “converted” from their nuclear mission in a way that does not render them incapable of accomplishing that mission. Such conversions are permitted under the New START treaty “by rendering [the Trident SLBM launchers and B-52H bombers] incapable of employing ICBMs, SLBMs, or nuclear armaments.”

For the Trident SLBM launchers, the conversion was done by removing gas generators of the ejecting mechanism from the launch tube and bolting the tube covers shut. The problem, for the Russians, is that this procedure is reversible, meaning that the launcher could still be used to launch SLBMs simply by removing the bolts and replacing the gas generators. Likewise, the B-52H modifications involve the removal of launch equipment from the aircraft. The aircraft still retains a socket that would allow the arming mechanism of a nuclear weapon to be connected to the removed equipment, which means the B-52H could be converted back to its nuclear role simply by reinstalling the equipment. According to Yermakov, “Russian inspectors are unable to verify the results of the re-equipping under the procedure stipulated by the Treaty.” From the Russian perspective, the issue of the noncompliant “conversion” of the Trident SLBM launchers and B-52H bombers is of “fundamental significance”; any extension of the New START can only be discussed, the Russians maintain, once the United States “fully return to complying with the spirit and the letter of the treaty.”

The foundation upon which U.S.-Russian cooperation regarding New START was constructed is fragile, founded as it was on the unilateral abrogation of the ABM Treaty in 2002, the ongoing compliance issue regarding the conversion of treaty-accountable items under New START, and the precipitous decision on the part of the Trump administration to withdraw from yet another landmark arms control agreement, the Intermediate Nuclear Forces (INF) Treaty, which went into effect Aug. 2. It would be the INF Treaty that would deal the fatal blow to U.S. credibility when it came to arms control.

The U.S. had, since 2014, accused Russia of violating the INF Treaty by testing a ground-launched cruise missile (GLCM) to prohibited ranges. According to the U.S. narrative, Russia took advantage of the existence of two other missile systems, the Kh-101 air-launched cruise missile and the Kalibr sea-launched cruise missile, to try and disguise the development of a new GLCM, the 9M729, which the U.S. claims was flight-tested to ranges prohibited by the INF Treaty. “Russia probably assumed parallel development—tested from the same site—and deployment of other cruise missiles that are not prohibited by the INF Treaty would provide sufficient cover for its INF violation,” then-Director of National Intelligence Dan Coats told Congress in January.

For its part, Russia denied that the 9M729 violated the INF Treaty. From the moment the U.S. first raised its allegations regarding the 9M729, Russia requested that they be backed up with facts that would substantiate the claims; this the U.S. refused to do. Finally, in an effort to forestall a precipitous U.S. withdrawal from the INF Treaty, Russia displayed the 9M729 alongside its cousin, the 9M728, a similar GLCM that the U.S. acknowledges complies with the range restrictions of the INF Treaty. The Russian Ministry of Defense invited U.S. and NATO military officers stationed in Moscow to attend this demonstration; none did. The Russians were able to demonstrate convincingly that the 9M728 and 9M729 missiles made use of the same propulsion components—solid-fuel rocket motors, which meant that, all things being equal, both missiles would fly the same distance. But there was a kicker—the 9M729 missile was equipped with an improved guidance and control package, as well as a different warhead which, in their aggregate, weighed significantly more than their counterpart components on the treaty-compliant 9M728 missile. In short, the Russians demonstrated that the 9M729 could not fly further than the treaty-compliant 9M728. The U.S. ignored this demonstration.

At the same time the U.S. was accusing Russia of violating the INF Treaty with the 9M729 missile, Russia was voicing similar concerns about the Mark 41 “Aegis Ashore” vertical launch system that the U.S. had installed in both Poland and Romania as part of its ballistic missile defense shield. The Mark 41 originally was designed for service on naval vessels. In this role, its launcher system could be configured to launch either the SM-6 surface-to-air missile, or the Tomahawk sea-launched cruise missile. From the Russian perspective, the Mark 41, when placed in a ground-launch configuration, became an INF-capable system, since it could launch a GLCM of proscribed range. The U.S. was adamant in its rejection of these claims, noting that the Aegis Ashore systems in Poland and Romania were configured to launch SM-6 surface-to-air missiles only. The Russians, however, insisted that there was no physical way to make this determination, noting that the INF Treaty required that similar systems be denoted with unique visually distinctive features; the U.S. dismissed the Russian position as a “technicality.”

On Aug. 18, the U.S. conducted a test launch of a GLCM from a Mark 41 launch cannister that had been bolted to a flat-bed trailer, making it a de facto ground launcher. The GLCM flew to ranges greater than those permitted by the INF Treaty. Technically, the U.S. was not in violation of the INF treaty at the time of the test, because it had expired on Aug. 2, some 16 days prior. But those 16 days hold the key to understanding just how seriously Russia took this test. According to a transcript of a meeting Putin held Friday with members of the Russian Security Council, he declared that by conducting a missile test a mere 16 days after the INF Treaty ended, it was “obvious that it was not improvisation, but became the next link in a chain of events that were planned and carried out earlier.”

From the Russian perspective, they had been right all along—the U.S. had cheated on the INF Treaty, just as they were cheating on the New START Treaty. With such a dismal track record of noncompliance, it is all but certain that the New START Treaty will not be extended and, thus liberated from any vestige of constraint, the U.S. and Russia will embark on a new arms race that threatens all of humanity with the all-too-real possibility of imminent destruction.