The Secret Service is a strange group. They don't really have a leader. It's not set up like a military. Each one is supposed to be able to act like a leader when something comes up.
I don't think you're going to be seeing the U.S. employing large army divisions to deal with small terrorist groups again. I don't think they're going to be occupying foreign nations in order to dry up terrorist groups within them. I think that lesson has been learned.