WARFARE EVOLUTION BLOG. I can speak to this topic with some level of experience. My old military intelligence unit, Army Security Agency (ASA) was the military arm of the National Security Agency (NSA). Our primary mission was to find, identify, fix, and track every significant military unit on the planet, including both our enemies and our allies. As Sun Tzu is credited with saying (or maybe it was Machiavelli, or Petrarch, or Michael Corleone): "Keep your friends close, and your enemies closer."