If the internet is primarily dependent on cables that run through oceans connecting different countries and continents. During a war, anyone can cut off a country’s access to the internet. Are there any backup or mitigant in place to avoid this? What happens if you cut the cable?



If the internet is primarily dependent on cables that run through oceans connecting different countries and continents. During a war, anyone can cut off a country’s access to the internet. Are there any backup or mitigant in place to avoid this? What happens if you cut the cable?

In: Technology

Cuting the cable cuts the internet. But it depends on the country. Cuting the internet to France is difficult, as there are multiple cables connecting France to other countries. But less developped countries are vulnerable. A few years ago, a cable was cut down in southern France, shutting down internet in most of Africa. Although backup cables existed, they couldn’t handle all of the traffic.

There isn’t just one cable there are lots of them and the information can be rerouted around any damaged sections. In the relatively early days of the internet lots of the cables ran directly under the twin towers. The fall of the towers added to the dramatic increase in the amount of traffic as people wanted to know what was going on brought the internet to a near standstill. Since then there are a lot more cables and redundancy built in to the system.

Think of it like closing an interstate highway. If I-95 suddenly disappeared, you could still drive from Miami to New York; you’d just have to take alternative (longer) paths, and you would be further slowed by all the other cars taking that route instead of I-95.

Internet routing works the same way. There are redundancies built into the system, whereby traffic will take an alternative path if its preferred route is blocked. Now if ALL the cables got cut and there were no alternative paths to take, then yes. The affected continents would be effectively cut off from each other for internet purposes.

Not necessarily in times of war, but there have been incidents of cable breach.

From time to time you’ll hear of large outages to say Southern California or Japan. These are a result of cable damage. Usually a result of large scale fishing trollers or petroleum exploration.

Technology and mapping have gotten better to help prevent this. GPS is now much more accurate. This is important in mapping where the cable is dropped and important on mapping where the vessel is trying to avoid the cables.

Picture your town and you wanted to dig a pool. Now you call the utilities and they come and paint lines across your property where underground service is located. In the early days of transatlantic and transpacific cabling, your utility company would only be able to say “yup we have cables buried under your block somewhere” and that was the closest info you could get.

As for redundancy… that costs money and has to be weighed against the likelihood of needing it. It would cost millions upon millions of dollars to drop a second run of cable. Is that expenditure risk worth it now that location can be better determined? That’s up to the service providers to account for.

In modern times, there are backups to the intercontinental cabling, with satellite based internet able to serve when the cables get cut off, plus there are more than just the one set of cables connecting everything.

Even without those cables or a backup, the internet would work just fine, you just wouldn’t be able to access other countries’ networks. It would splinter the internet into fragments, with China’s Internet unable to connect to America’s Internet, which in turn would be unable to connect to Europe.

But Microsoft could build a server farm in America and allow people to play their XBOX just fine.

As for why they use these cables instead of satellites normally, it’s because the distances are greatly increased beaming the signal up into space to be bounced around the planet, and latency would be increased to an intolerable level, so satellite internet is currently limited in scope for remote areas, where sending cables and fiber optics are not feasible.

On top of redundant cabling others have mentioned, even if you managed to cut every single cable that goes into a country they would not be fully cut off from the internet(although their bandwidth would be miniscule by comparison). Satellite connections to the internet are available around the globe and, short of blowing up all comm satellites, impossible to block.

Hitting the undersea cables is a common tactic during war. It was a specific focus during the Cold War in fact. Both the US and Russians spent a lot of effort locating and either accessing or mining their opponent’s undersea cables. The US even figured out a way to passively tap Russian cables early on.

Now a days there are a lot more cables and much more commercial use for them. Check out https://www.submarinecablemap.com.

Finding all the cables would not be easy, especially in the depths of the major oceans. The military also has satellite communications so losing physical cables would have less impact.

Few years back a grandmother in Georgia (the country) accidentally severed a line while gardening. Took the entire country off line for weeks.

The internet has massive redundancy and the ability to route around broken (or even just slow) connections. That’s one of its design principles.

Before internet but after cables in wwi britain cut all the cables from Europe to america that didn’t go through the uk. Those they tapped. This led to intercepting the zimmerman telegram and the us declaring war on germany.

There are a lot of good replies here. I would also like to point out that the cables are very hard to locate and very hard to access.

Once the cable is shored, it is buried 2m under the surface. Thats usually to about 70-100′ of water. Afyer that they are laid on thw surface but eventually get buried. Once laid they are only mapped after and that always changes due to a few factors.

If there is a shallow water break we just run a new shore in and leave the old cable where it lays. Just way to much hassle to find and deal with.

Omce in deep water you need very specialized vessels, location equipment and service equipment to deal with it. Not to mention not people people in the world do this kind of work.

I guess you might be able to luck out with an ROV but odds are not great. Once done most major countries have multiple redundancies and can get it repaired pretty quick.

Depending on how you define it, the internet isn’t primarily reliant on international cables. You (usually) only use those cables for international routes. Most big services will have a ‘local’ presence or at least a cache in a data center within your region. Your in-country internet will largely keep running and even international routes will reroute via less efficient options – either longer routes, cross land border cables, terrestrial microwave,or even satellite backups for those with enough money to purchase them. That’s what the internet was primarily designed to do, by DARPA. It’s quite good at doing so.
Also, in most western countries at least, there’s a lot of cables. It’s not trivially simple job to cut them all & everyone would get very ‘excited’ by their loss…

One of the chief design goals of the internet was its durability. The internet as it exists now, particularly with the web, is very different in design and purpose than its origins as a tool for military communications during the Cold Wars.

The goal was that there was no “central hub.” There isn’t even a singular internet. It’s just various communication tools connected to one another. If one gets cut off, that’s not going to crash the whole system. You could split it in two, and each half will function perfectly fine, just as if you had simply disconnected one device.

While there’s been a lot of infrastructure built up around the internet that does give elements of centralization to various extents (see what happens when AWS or Cloudflare goes down), the core of the internet’s design remains in place. A web service outage might cause a lot of websites to go down, but it’s not going to stop your online game session. A state might cut off its internet to suppress protests, but that’s not going to stop the functionality of the internet for other countries.

I don’t know why people are getting so heated about internet infrastructure, but *seriously!?* If you’re getting this upset about coaxial cable go eat a snickers and take a walk.

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