The threat of nuclear war and terrorism "seems more manageable" than four national security challenges that stem from rapid, global technological development, according to U.S. National Security Agency general counsel Glenn Gerstell. 

Gerstell, who is stepping down later this year, detailed the security risks that concern him the most while speaking on Jan. 15 during an American Bar Association event in Washington, D.C. His speech was later posted on Lawfare. 

"The first challenge is surely China, an adversary and partner rolled into one. There isn't a better example of how technology knows no boundaries and how global technological development and trade produce complicated interdependencies," he said.