On July 11, 2021, shortly after four in the afternoon local time, Cuba’s internet traffic fell to zero.
That is not a metaphor. The network analysis firm Kentik recorded it: the country’s BGP routes collapsed all at once. Its director of internet analysis, Doug Madory, explained why this could not have been a fault or congestion from too many users: when a network is overwhelmed, service degrades gradually, it slows down, it stutters. What was seen in Cuba was an abrupt cut. Someone flipped a switch.
What BGP is, and why it is the switch
The internet is not one network. It is tens of thousands of independent networks that agree to pass traffic to each other. That agreement is announced with a protocol called BGP, which essentially says: “these addresses are reachable this way”. Each operator announces its ranges and the rest of the world learns the path.
If an operator stops announcing its routes, it stops existing for everyone else. No cable needs cutting, no antenna needs pulling down: withdrawing the announcement is enough. Packets looking for the island are left without a road and are dropped. It is the difference between bricking up a door and erasing the address from the map.
That is why the cut looks so clean in the data, and why Madory could state it was deliberate. A power failure or a broken cable leaves a different trace.
Why it is so easy in Cuba
In most countries several operators compete. Switching off the national internet requires coordinating many companies, and each one is a witness and a leak.
Not in Cuba. ETECSA is the country’s only telecommunications operator, and it is state-owned. All connectivity for eleven million people runs through a single company answering to a single owner. No court order is needed, no consensus, no one to convince. It is a phone call.
That is the structural vulnerability, and it has no technical fix: it is political by design. A country with one operator has one switch.
What happened next, which is the genuinely instructive part
Precision matters here, because the idea that Cuba spent “four days without internet” gets repeated a lot, and it was not quite like that.
The total blackout was short: about thirty minutes, followed by several hours of partial outages. Destroying a whole country’s connectivity is expensive, visible from outside, and damaging to the state itself, which needs its own systems.
What came next was smarter and cheaper: targeted blocking. NetBlocks measured the disruption of WhatsApp, Facebook, Instagram and some Telegram servers across ETECSA’s network, including the Cubacel mobile service, and later restrictions on YouTube and Google’s video servers as well. That disruption ran, by their measurements, from July 12 to 18. Independent Cuban outlets placed the restoration around the 15th. The exact date varies depending on who measured and from where, but the pattern does not: it was days, not minutes.
And there is the lesson. They did not need to leave the country without internet. They needed to cut the channels that carried the images out. Everything else could keep running: banking, official mail, television. A total blackout is an international headline. Blocking WhatsApp is almost invisible from outside and does exactly the same job.
What this teaches
Modern censorship is not about switching off the internet. It is about deciding which parts of the internet stay on. It is surgical, reversible at any moment, and easy to deny: ETECSA called it an “affectation” at the time.
It also teaches something about price. If the regime was willing to cut the entire country, even for half an hour, it is because what was traveling over those networks looked more dangerous than the cost of switching them off. The images of that Sunday were worth that much.
One last fact, which deserves its own article: while the platforms were blocked, around a million and a half Cubans found a way out anyway. I will tell that story separately.