I think the big lesson of the Millennium Challenge is that
a smart, motivated adversary will always go for the weak link in your victory conditions. And that is usually your blind spots, by definition. They won't attack you where you've prepared; they'll look for the areas where you are
not expecting vulnerability and attack there.
All stuff Sun Tzu wrote 2500 years ago, but very hard for a bureaucracy to internalize, because by definition bureaucracies are formed to solve known problems and are blind to their blind spots.