Clay Blair, Jr. was an American historian, best known for his books on military history. Born in Lexington, Virginia, he served on the fleet submarine Guardfish (SS-217) in World War II and later wrote for Time and Life magazines before becoming editor-in-chief of The Saturday Evening Post. He assisted General Omar Bradley in the writing of his autobiography, A General's Life (1983), published after the general's death. Blair wrote two dozen history books and hundreds of magazine articles that reached a popular audience. His last book was Hitler's U-Boat War: The Hunted, 1942–1945 (1998), which followed Hitler's U-Boat War: The Hunters, 1939–1942 (1996).
Blair's history of the Korean War The Forgotten War: America in Korea, 1950–1953 (1987) is considered one of the definitive historical works on the war. His work was notable for his criticism of senior American political and military leaders. Blair criticizes President Harry S. Truman and his Secretary of Defense, Louis A. Johnson, for failing to maintain the military's readiness in the years immediately following World War II. His history, while comprehensive, primarily employs a top-down perspective, with less emphasis on individual soldiers than on larger operational issues and the perspectives of general and field-grade officers. He has also been criticized by some historians for not making sufficient use of Communist sources.
Blair also wrote extensively on the submarine war of World War II, notably in the bestselling Silent Victory: The U.S. Submarine War Against Japan (1975), considered the definitive work on the Pacific submarine war.
Blair was married for many years to Joan Blair, who co-wrote some of his books. Prior to that marriage he was married to Agnes Kemp Devereux Blair, with whom he had seven children: Marie Louise, Clay III, Sibyl, Joseph (deceased), Kemp, Robert and Christopher.