Resilience
One of the primary purposes for which the internet was built, is to maintain communications even in cases of a partial blackout. When a part of the network goes dark, packets route around it. But the resilience of the internet varies greatly over different regions.

According to Jim Cowie, Chief Scientist at Dyn Reseach, an important measure of a country's internet resilience is decentralization. The larger the number of Network Service Providers (NSPs) that provide a link between a country's networks and the global internet, the more resistant the local network is against blackouts.

In 2012 Cowie created a map showing the risk of a country being cut off from the internet. Ranging from severe risk to resistant. (At the time he was still founder and CTO of Renesys, the internet monitoring company which was acquired by Dyn Research in 2014.)
 
Severe risk: less than 3 internationally-connected NSPs. Significant risk: fewer than 10 NSPs. Low risk between 10 and 40 NSPs. Resistant: more than 40 NSPs. 
 

In a 2013 interview with Elektor Ethics Cowie said: ‘I often am asked by people if their part of the internet can be taken offline as happened during the blackouts in Egypt and Syria. I think that in Western Europe and the United States there aren’t really many threats left to the Internet. The internet has grown so wonderfully diverse in these places that in terms of being attacked or people taking the Internet offline it really can’t happen anymore. It’s beyond that stage.’