John Boyd was a fighter pilot in the Korean War, an instructor at the US Air Force Fighter Weapons School, and arguably America's greatest military thinker of the 20th Century. His concept of the OODA Loop helped guide the US military during two wars against Saddam Hussein's Iraq. This 4000-word 'long essay' was originally prepared for the War in the Modern World program at King's College London by Daniel Ford, an American journalist and historian. Revised 2014. With illustrations, source notes, bibliography, and a chapter from the author's book, A Vision So Noble.

Daniel Ford has spent a lifetime reading and writing about the wars of the past hundred years, from the Irish rebellion of 1916 to the counter-guerrilla operations in Iraq and Afghanistan. He is best known for his history of the American Volunteer Group--the 'Flying Tigers' of the Second World War--and his Vietnam novel that was filmed as Go Tell the Spartans, starring Burt Lancaster. Most recently, he has turned to the invasion of Poland in 1939 by Germany and Soviet Russia. Most of his books and many shorter pieces are available in digital editions He lives and works in New Hampshire.