Sunspots can fry satellites and communication disruption via flares is common, extremely common. Anyone who operates a international communications system like a phone company or ISP keeps track of sunspot activity and the military issues a daily forcast of the electromagnetic spectum That possibility and the fact that running a fiber for 10 thousand miles is actually cheaper than launching a sat, just like cacosapo mentioned. In addition satelite contingency links would be like putting the continent on 56k dialup (in relative terms). And only critical subscribers would get access I bet. It's not even a fraction of the bandwidth. Fiber links terminate at specific locations and even though multiple links exist, any one of those would cause serious issues. For instance Guam and Hawaii are both international sort of fiber exchanges for Asia. The cables hover a few hundred feet below the surface, they just float there and maintenance ships come along and scoop them up and run them through that hull to maintain and check them. I have talked to both engineers and service ship personal over many beers, plus I dove down just to look at one and see what it looked like outside of a contained facility. In this instance it was owned by ATT. A major fiber cut is only a few hours down time assuming someone doesn't set up a military perimiter around it. But given the backup capability of the US military command and control structure, it would be stupid to cut them. The terrorist or who ever does the deed will lose their own command structure and would have to resort to key word commands on Arabic television, but that may be out as well. Just a different take. :)
