Most Americans recognize the name of John Birch because of the high-profile and often controversial anti-communist John Birch Society founded in his honor. But few people know the true story of this courageous Christian missionary and United States intelligence agent, to whom countless American airmen in China during World War II owe their lives. Even fewer know the story of his brutal murder, which was covered up by U.S. government officials for years.   James & Marti Hefley's book reveals the background of this patriotic young man who was gunned down and mutilated by Chinese Communists 12 days after the war ended and who many believe was the true unsung hero of the China War Theater in World War II. Captain John M. Birch, the son of devout Christian parents, landed in China in 1939 when he was barely 22 years old. Entering language school, he became fluent in Chinese in order to begin work as an itinerant missionary. The advancing Japanese army soon changed his plans. He went on to become an intelligence officer for Gen. Claire Chennault, legendary leader of the Flying Tigers of World War II fame, who described Birch as "more valuable to me than any pilot" for his rugged, dangerous work behind Japanese lines.   The truth of who John Birch was and what he stood for negates the preconceived notions many Americans may have of this World War II figure and depicts him as the crackerjack Chennault sent out to rescue American airmen who were shot down in remote areas of China. The story line takes the reader through a gamut of emotions--from the sense of security created by his warm, loving family, to his love for the people of China, where he was known as "Bey Shang We." Birch's strong view of patriotism, coupled with his romance with a Scottish nurse, give a sense of joyous release when victory is won in China. This contrasts vividly with the visualization of his mutilated body and the ensuing cover-up of his murder, theoretically to keep Americans from rising in their wrath and vetoing further appeasement of communism in that post-World War II China era.   The file, for decades marked SECRET and placed under lock and key, was finally declassified in 1972 through the Freedom of Information Act. Through countless interviews with military officials, Birch's officer colleagues, members of the Birch family, and other organizations, the Hefleys piece together an unprecedented look into the life of this intriguing and misunderstood war hero.