Further to David’s previous posts on this, John Robb is working the problem too. Three observations from him:
Vulnerability. All of the same network vulnerabilities we see other infrastructures are in force with the Internet’s long haul systems (the network analysis of systempunkts applies). If this was a real attack rather than a series of accidents (the geographical concentration is interesting in this regard), then this was likely a capabilities test that yielded data on response times, impact, and duration.
Means. Attacks on undersea cables are within the capacity of small groups to accomplish. With precise mapping (these cables take very circuitous routes), a cable could be cut with as little as an anchor. However, nation-states are the most capable in this sphere (including, a growing number of micropowers). Why would a nation-state do this? Deterrence. Disconnection from the global communications grid is very likely become a form of economic/social coercion in the future (for standard national security reasons all the way down to an inability/unwillingness to crack down on rampant Internet crime, which is growing into a HUGE global problem).
Precision. It’s very hard to precisely target an attack’s damage. Regional impacts are unavoidable (collective punishment for everyone that connects to the target country?). Here’s a final point to consider: closed systems like China’s that route traffic through firewall choke-points, or other closely held infrastructure, are likely very vulnerable to an attack of this type.
Also: Valdis Krebs offers a pre-9/11 take on how social network analysis can be applied to computer networks to make them more resilient…