You might have heard that North Korea launched an intercontinental ballistic missile this week. Well, not in Russia! The Russian government is stubbornly insisting that the missile launched by North Korea on Tuesday morning was merely a medium-range ballistic missile, capable of traveling no more than a thousand kilometers or so. That’s what the Russian mission to the United Nations Security Council said on Thursday, anyway.

All of this raises a disquieting thought: Did the Russians miss the launch? Maybe the Russians are just being stubborn, but is it possible that Russian radars and warning satellites are so lousy, they might not see a North Korean ICBM climbing to seven times the altitude of the International Space Station? And could that technology gap start an accidental nuclear war between the United States and Russia?

Consider this. If North Korea fired an ICBM at the United States, the American military would attempt to shoot the missile down using the 36 ground-based interceptors located at Fort Greely, roughly 100 miles southeast of Fairbanks, Alaska. The plan would be to fire several—four or five—interceptors at each incoming North Korean missile. If we get lucky, one of those interceptors strikes the missile and destroys it. Here is a stray thought, though: What happens to the others?

U.S. missile defenses use kinetic energy, not explosives, to destroy enemy missiles—the “kill vehicle” simply slams into the target. The kill vehicle carries no explosives, which means the kill vehicles that don’t hit the target simply continue on their merry way, re-entering the atmosphere and, for the most part, burning up. For scenarios in which the Alaska site shoots at a North Korean missile, the kill vehicles should mostly re-enter the atmosphere over Russia.

You might feel a twinge of unease, thinking about a large number of U.S. missiles streaking into Mother Russia, lighting up Moscow’s early warning system before burning up. The Russians would know we aren’t attacking them, right? I mean, they wouldn’t do something crazy like get out the Cheget , their version of the nuclear football used to launch a nuclear retaliation, would they?

Well, they might. First of all, they might not see the North Korean launch in the first place. In 2009, the Russians missed a North Korean space launch. Russia’s early warning network fell on hard times after the collapse of the Soviet Union and was pretty spotty back then. After the 2009 fiasco, Russia built a new radar that was supposed to provide better coverage of North Korea. But if that radar is working so well, how come Russia thinks the Hwasong-14 is a medium-range missile?

Moreover, we can’t assume that Russia would realize the launch from Alaska was a missile defense interceptor rather than an ICBM. From Russia, the trajectories might appear quite similar, especially if the radar operator was under a great deal of stress or pressure. In 1995, for instance, the Russian military mistook the launch of a sounding rocket from Norway for a launch of a nuclear-armed Trident missile from the sea and alerted Boris Yeltsin. The Norwegian rocket was actually flying away from the Russia, but it took several very tense minutes for the Russian warning system to figure that out.

It doesn’t matter how Russia’s early warning system ought to work on paper, the reality of the Russian system in practice has been a lot less impressive.

Nor can the United States simply call up the Russians. The timeline for a missile defense intercept is so tight—just a few minutes—that the president probably won’t even know about an intercept until after it happens. After the 1995 incident, the United States and Russia agreed to try to solve these kinds of problems by establishing a “Joint Data Exchange Center” to make sure that both sides had the same early warning data—like, “Hey, look, it’s a North Korean ICBM. We’re going to shoot that.” But Russia slowly strangled the JDEC idea and it never went anywhere. A reporter described the abandoned site in 2001 as “windows boarded up or cracked, its walls marked with graffiti” and serving “mostly as a clandestine hangout for young beer drinkers.”

A small number of us pushed the Obama administration to make another effort to revive JDEC. I recall sitting in a meeting at the Pentagon where I asked a senior official how he planned to overcome the obstacles that had stalled JDEC during the Bush administration. He assured me they had the situation under control. They were going to establish a joint data “fusion” center with Russia. This might shock you, but simply changing the name didn’t help.

Then there is the disturbing possibility that even if Russia realized the launch was coming from Fort Greely, Putin might still think it was a sneak attack. When he was secretary of defense, Robert Gates stated that the Russians were convinced that the U.S. planned to secretly install nuclear-armed missiles in missile defense silos, a remark that a senior Obama official later told me he was shocked to hear in an unclassified setting.

The Russians also made a big stink in New START negotiations about banning the placement of offensive missiles in missile defense silos (and vice versa), something that surprised negotiators. It seems crazy, but it really seems there are some Russian military and political officials who think the U.S. would use nuclear-armed missiles from missile defense sites in a sneak attack. Putin even said it to Oliver Stone: “The launchers of anti-missile ammo can, in a few hours, be converted carry to attack missiles.”

All of which is to say it is plausible to imagine a scenario in which the rocket jockeys sitting at Fort Greely are high-fiving each other after knocking a North Korean ICBM into smithereens, only to see the big board suddenly light up with a full-scale Russian bolt-from-the-blue. In the current environment, it would appear to be an “act of madness” to actually try and intercept a North Korean ICBM using the system in Alaska.

We should probably do something about that. One solution is to try to revive proposals for U.S. and Russian cooperation on early warning. It’s a good idea whether we call it a data exchange or fusion center. But to be honest, I doubt the Russians are very interested. Maybe Trump will just let them hack their way in, if they haven’t already done so. Another step might be to ban nuclear-armed missile defenses and agree to let Russian and American inspectors visit missile defense sites to ensure they they are not nuclear armed. Congress has prohibited the Pentagon from even thinking about nuclear-armed missile defenses, but the system around Moscow still depends on nuclear warheads.

But even with these measures, it is hard to be confident that Russia would detect and correctly interpret a large number of launches out of Alaska. There is just too much that can go wrong. The answer may simply be that we can’t rely on the Fort Greely site to defend against North Korean attacks, at least not without running unacceptable risks of sparking an accidental nuclear war with Russia.