In nearly nine years as head of the nation’s largest intelligence agency, Gen. Keith Alexander presided over a vast expansion of digital spying, acquiring information in a volume his predecessors would have found unimaginable.
In Iraq, for example, the National Security Agency went from intercepting only about half of enemy signals and taking hours to process them to being able to collect, sort and make available every Iraqi email, text message and phone-location signal in real time, said John “Chris” Inglis, who recently retired as the NSA’s top civilian.
The overhaul, which Alexander ordered shortly after taking leadership of the agency in August 2005, enabled U.S. ground commanders to find out when an insurgent leader had turned on his cellphone, where he was and whom he was calling.
“Absolutely invaluable,” retired Gen. David H. Petraeus, the former U.S. commander in Iraq, said in an interview as he described the NSA’s efforts, which led to the dismantling of networks devoted to burying roadside bombs.
Alexander “sped the place up,” Inglis said.
But something else seems likely to shape the legacy of the NSA’s longest-serving director, who retired Friday: something that Alexander failed to anticipate, did not prepare for and even now has trouble understanding.