His writing has also appeared in such publications as the Los Angeles Times, The Atlantic Monthly, Harper's Magazine, The New Yorker, The Christian Science Monitor, Playboy and Rolling Stone.

In spring 2006, Cooper was appointed a full-time member of the journalism faculty at the USC Annenberg School for Communication for the academic year 2006–2007.

He ruffled many ideological allies by his criticism of Mumia Abu-Jamal, whom he famously dismissed as "a bad choice for poster-boy of the anti-death penalty movement.

"[5] Cooper also disparaged Ward Churchill, calling him a "guaranteed loser" who was "an irrelevant and clearly deranged loner on the edge of the looniest left.

"[6] Cooper was vocal in his opposition to the 2003 invasion of Iraq and the subsequent occupation, but he has been scathingly critical of other leftist opponents to the war, such as Canadian journalist Naomi Klein, who he lambasted as a "friend" and "apologist" for prominent Iraqi Shiite Islamist Muqtada al-Sadr in response to a piece she wrote for the September 13, 2004 edition of The Nation.

Cooper has also been harshly critical of Venezuelan president Hugo Chávez, whom he regards as a "thug," and very supportive of the Ukrainian Orange Revolution in 2004. Cooper has criticized the liberal position on gun control, and has written that he is "tired of and deeply annoyed by affluent liberals--living in 6,000-square-foot houses with heated swimming pools, who use a 400-horsepower SUV to drive their kids two blocks to school, with a family carbon footprint that of a small battleship".

[7] Over the past few years Cooper has sharply criticized the Cuban government for its crackdown on internal dissidents—some of whom have been handed stiff sentences for receiving funds and instructions from the United States.

Cooper has published three books: Roll Over Che Guevara: Travels of a Radical Reporter (1994), an anthology of his journalistic pieces;[8] Pinochet and Me: A Chilean Anti Memoir (2001) which was an L.A. Times best-seller;[3] and The Last Honest Place in America: Paradise and Perdition in the New Las Vegas (2004).