It’s still not known who disconnected Syria’s Internet from the rest of the world last Thursday, but on Saturday someone turned it back on. The restoration, according to Renesys, a networking firm that tracks Internet connections, “was achieved just as quickly and neatly as the outage: like a switch being thrown.” The episode brought to mind a similar one in Egypt at the beginning of last year.

Shutting off an entire country’s connection to the rest of the world is obviously not as simple as throwing a switch. But imagine for a moment that such a metaphorical switch does exist. How hard is it to throw?

The answer depends on on how diverse a given country’s Internet infrastructure is. Generally, the greater the number of organizations within the country responsible for assigning IP addresses and routing traffic in from and out to the global network, the more complicated the task of completely disconnecting. In countries like Syria, Egypt, and Iran—where the Internet is highly regulated and control of traffic is confined to a few entities—the “switch” is much easier to throw.

Below is an up-to-date map in which countries are colored according to the Internet diversity at what the Renesys calls the “international frontier.” Citizens in countries colored dark green face “severe risk” of disconnection from the rest of the world. Countries colored the lightest green shade are the most “resistant,” according to Renesys.