Any cyber-warrier worth paying would be prepared for a connection cut. The cool thing about botnets is that they live on your target's own soil. You could failsafe 'em so that once armed, if they lose touch with the mothership they could carry out a specified program of attack. C&C for a botnet doesn't have to be fast, so dribbling commands around a cable cut or other disruption could be accomplished. After all, the whole point of the internet was survivability of the C&C network when links were severed by atomic explosions. For cold war type situations, agents in-country running otherwise respectable businesses (with fat pipes) could control cyber warfare assets as a sideline. It's all so easy.

And lets not forget the role of sabotage in cyber warfare. Our physical network infrastructure is probably not that robust. It may be easier to down the root servers with a backhoe than with a hack.

Face it, the West is naked and spreadeagled when it comes to cyber vulnerability, and probably always will be. The chinese are far less dependent on the internet for commerce. Of course, if the 'net goes down, millions of chinese teeners may attack their parents with knives, so perhaps our evil plan will unfold in a different way.