Which Countries Are Most at Risk from Internet Disconnection

Syria recently shut-off access to the internet in its country. This was fairly easy to do because only two firms provided internet service in the country.

James Cowie of renesys writes:

The key to the Internet's survival is the Internet's decentralization — and it's not uniform across the world. In some countries, international access to data and telecommunications services is heavily regulated. There may be only one or two companies who hold official licenses to carry voice and Internet traffic to and from the outside world, and they are required by law to mediate access for everyone else.

Under those circumstances, it's almost trivial for a government to issue an order that would take down the Internet.... 

With good reason, most countries have gradually moved towards more diversity in their Internet infrastructure over the last decade. Sometimes that happens all by itself, as a side effect of economic growth and market forces, as many different companies move into the market and compete to provide the cheapest international Internet access to the citizenry...Here's a map of the world, with countries colored according to the Internet diversity at the international frontier. We did a census, from our own view of the global Internet routing table, of all the domestic providers in each country who have direct connections (visible in routing) to foreign providers.