“The young pilot walked away from his commitment in 1972 — the same year the U.S. military implemented random drug tests.”

One of the persistent riddles surrounding President Bush’s disappearance from the Texas Air National Guard during 1972 and 1973 is the question of why he walked away. Bush was a fully trained pilot who had undergone a rigorous two-year flight training program that cost the Pentagon nearly $1 million. And he has told reporters how important it was to follow in his father’s footsteps and to become a fighter pilot. Yet in April 1972, George W. Bush climbed out of a military cockpit for the last time. He still had two more years to serve, but Bush’s own discharge papers suggest he never served for the Guard again. —Salon