American intelligence agencies have less trouble getting information, than in finding ways to store it. This situation changed in the 1990s as fiber optic cable became the cheapest way to move huge amounts of electronic data at the speed of light. One of the major money pits during the dot.com boom was companies laying hundreds of thousands of kilometers of fiber optic cable across land and under the sea, replacing the older, much lower capacity, copper cables. The U.S. has a modified nuclear attack submarine that could tap into those undersea cables, and did so successfully several times. But these...