Rob Harris, the movie's publicist, told the Albuquerque Journal the film is expected to start shooting in northern New Mexico this November.
Ronson's book is about the U.S. Army's alleged experimentation with psychological warfare techniques, including its attempts to use brain waves to kill goats and rock music to torture suspects, the newspaper noted.
Clooney won an Oscar for his work in "Syriana." He was nominated for another earlier this year for his performance in "Michael Clayton" and can now be seen in "Burn After Reading."
McGregor starred in the "Star Wars" prequels, as well as "Trainspotting," "Moulin Rouge" and "Big Fish."