The lines that tie the globe together by carrying phone calls and Internet traffic are just two-thirds of an inch (1.68 centimetres) thick where they lie on the ocean floor.

The foundation for a connected world seems quite fragile, an impression reinforced this week when a break in two cables in the Mediterranean Sea disrupted communications across the Middle East and into India and neighbouring countries.

Yet the network itself is fairly resilient. In fact, cables are broken all the time, usually by fishing lines and ship anchors, and few of us notice. It takes a confluence of factors for a cable break to cause an outage.

“Most telecom companies have capacity at multiple systems, so if one goes out, they simply reroute to a different system,” said Stephan Beckert, analyst at research firm TeleGeography in Washington. “It’s just that in this case, both the main route and the back-up route got cut for a lot of companies.”

The two cables — FLAG Europe Asia and SEA-ME-WE 4 — were cut on the ocean floor just north of Alexandria, Egypt.

By an accident of geography and global politics, Egypt is a choke point in the global communications network, just as it is with global shipping. The reasons are the same: The country touches both the Mediterranean and the Red Sea, which flows into the India Ocean.

The slim fibre-optic cables that carry the world’s communications are much like ships, in that they’re the cheapest way for carrying things over long distances. Pulling cable overland is much more expensive and requires negotiation with landowners and governments.

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