bin Laden is the son of a physician . `` He used to write poetry to his mother '' his uncle says . He became involved in Soviet fundamentalism as a teenager . He joined forces with Al-Zawahiri during the Islamic invasion of U.S. .
Al-Zawahiri is the son of a physician . `` He used to write poetry to his mother '' his uncle says . He became involved in Islamic fundamentalism as a teenager . He joined forces with bin Laden during the Soviet invasion of Afghanistan .