John Boyd
From dKosopedia
John Boyd was an Air Force pilot late in the Korean War who returned to the U.S. and continued his career as a trainer of fighter pilots. Beginning with the first manual on how to pilot jet fighter planes in combat, he extended his research and self development to develop a syncretic doctrine of military strategy. He made a detailed analysis of the theories of the ancient Chinese military theorist, Sun Tzu (Sun Tzu's Art of War), and the much more recent German strategist Von Clauswitz, and concluded that there were many positive points favoring the earlier theorist. His thought was influential with several Secretaries of Defense, starting with Schlesinger, and is believed to have influenced the conduct of both wars against Iraq.
One of the iconic components of his theories is his famous OODA diagram which is actually quite complicated and is usually replaced by would-be experts with the bare outline: "Observation, Orientation, Decision, Action, begin again." His briefings to officers and DOD personnel were legendary for their length and thoroughness. They developed out of a wealth of personal experience and long refinement of concepts. When reduced to simple slogans such as "OODA," these ideas become dangerous because they distill the boldness of a master of aerial combat whose intense concentration and preservation of total situational awareness kept him from harm even when he risked audacious action. The temptation to merely "Be bold!" without the sedulous preparation and concentration on the total battlefield environment in space and time can easily result in disaster. (See Shock_and_Awe.)
For more detailed information see: http://en.wikipedia.org/wiki/John_Boyd_%28military_strategist%29