It might seem like a nightmare scenario. A terrorist organization or nefarious nation state decides to derail the global internet by faulting the undersea fiber optic cables that connect the world. These cables, which run along the ocean floor, carry almost all transoceanic digital communication, allowing you to send a Facebook message to a friend in Dubai, or receive an email from your cousin in Australia.

US Navy officials have warned for years that it would be devastating if Russia, which has been repeatedly caught snooping near the cables, were to attack them. The UK’s most senior military officer said in December that it would “immediately and potentially catastrophically” impact the economy were Russia to fault the lines. NATO is now planning to resurrect a Cold War-era command post in part to monitor Russian cable activity in the North Atlantic.

The idea of the global internet going dark because some cables were damaged is frightening. But if Russia or anyone else were to snip a handful of the garden hose-sized lines, experts say that the consequences would likely be less severe than the picture the military paints. The world’s internet infrastructure is vulnerable, but Russia doesn't present the greatest threat. There are plenty of more complicated problems, that start with understanding how the cable system actually works.

Russia snipping a handful of cables in the Atlantic, where its submarines have been spotted, would disturb the global internet very little.

“The amount of anxiety about somebody sabotaging a single cable or multiple cables is overblown,” says Nicole Starosielski, a professor at New York University who spent six years studying internet cables to write the The Undersea Network. “If somebody knew how these systems worked and if they staged an attack in the right way, then they could disrupt the entire system. But the likelihood of that happening is very small. Most of the concerns and fears are not nearly a threat at all.”

For one, ruptures aren’t exactly an anomaly. One of the estimated 428 undersea cables worldwide is damaged every couple of days. Nearly all faults aren’t intentional. They’re caused by underwater earthquakes, rock slides, anchors, and boats. That’s not to say that humans are incapable of purposefully messing with the cables; off the coast of Vietnam in 2007, fishermen pulled up 27 miles of fiber cords, disrupting service for several months. (It wasn't cut off completely, because the country had one more cable that kept the internet going.)

You don’t notice when a cable faults, especially if you live somewhere like the United States, because your Instagram message or Google Voice call is instantly re-routed. If you’re Skyping with a friend in Romania for instance, and a fishing boat or anchor ruptures a cable—as causes two-thirds of faults—your conversation simply goes over another line. Many regions, like Europe, the United States, and East Asia have numerous cables running over the same path. You can check out a map of them all here.

That means Russia snipping a handful of cables in the Atlantic, where its submarines have been spotted, would disturb the global internet very little. In fact, even if it ruptured every single cable in the Atlantic Ocean, traffic could still be re-routed the other way, across the Pacific.

“It wouldn’t work very well or be the highest quality, but it’s not like there wouldn’t be any communication happening,” says Alan Mauldin, research director at TeleGeography, a market research firm that specializes in telecommunications, including undersea cables.

Even in a hypothetical, Black Mirror-esque world in which Russia somehow chops every cable that connects to the United States from every side, the internet would not go out like a light. Americans would still be able to utilize land networks that connect the continent; it would just be impossible to communicate overseas.

“You can still email people in the US if all submarine cables were gone,” says Mauldin. “But people in Europe wouldn’t see your silly cat video you posted on your Facebook profile.”