Here is an article on Leadership by Bill Cohen. If you are interested in leadership academically or how to be a leader practically it is worth reading. He uses some very interesting examples of people who leveraged the respect that came from being masters of their fields into great feats of leadership.  Medal of Honor winner Sargent York for instance was a great marksman.  Be sure to scroll down on the page that this link takes you to:

Know Your Stuff by Bill Cohen

Full disclosure. Bill was a consultant to my company Brandon International, is a friend, interviewed me for his book The Stuff of Heroes and has a wife named Nurit. He is also brilliant, intense, a warrior and has more energy than most people half his age.