Few figures in the past quarter-century have played a more significant role in American foreign policy than Colin Powell. He wielded power at the highest levels of the most important foreign policy bureaucracies: the Pentagon, the White House, the joint chiefs, and the state department. As national security advisor in the Ronald Reagan administration, chairman of the joint chiefs of staff under George H.W. Bush and Bill Clinton, and secretary of state during George W. Bush's first term, he played a prominent role in four administrations, Republican and Democrat, spanning more than twenty years.