Manning revealed that he had contacted the Washington Post and the New York Times, and got nowhere, before deciding to give his news to WikiLeaks, from which it would ultimately reach those two newspapers and many more.
Manning said he released only information that he was certain would not harm the United States. There's no evidence he was wrong.
He released evidence of crimes, as anyone able to do should do. Manning did so out of an actual belief in democracy (as distinct from "democracy" as a justification for bombings).
"We were obsessed with capturing and killing human targets on lists and ignoring goals and missions," Manning said on Thursday of his time in Iraq with the U.S. Army. "I believed if the public, particularly the American public, could see this it could spark a debate on the military and our foreign policy in general as it applied to Iraq and Afghanistan. It might cause society to reconsider the need to engage in counter terrorism while ignoring the human situation of the people we engaged with every day."
P.P.S. RootsAction is an independent online force endorsed by Jim Hightower, Barbara Ehrenreich, Cornel West, Daniel Ellsberg, Glenn Greenwald, Naomi Klein, Bill Fletcher Jr., Laura Flanders, former U.S. Senator James Abourezk, Coleen Rowley, Frances Fox Piven, and many others.