For Ellsberg, President Bush’s policies bear a “frightening” resemblance to those of the Nixon administration. In many ways, he says, it makes the publication of his memoir and continued study of Vietnam increasingly relevant.

“This has some very strong analogies to Vietnam in a way that disturbs me very much,” he says. “It’s as though we haven’t learned very much.”

He points to recent Bush administration discussions of potential attacks on Iraq as “catastrophically risky” and “extremely unwise.”

“I’m very disturbed to see Congress going along with an attitude in the White House that the president has a right to decide by himself whether we go to war or not and who we go to war against,” he says. “I worked for a president who lied us into war in 1965. He manipulated Congress into the Tonkin Gulf Resolution.”

And he criticizes the resolution of support passed by Congress last September, which authorized Bush to use “all necessary and appropriate force” against those responsible for the Sept. 11 terrorist attacks—calling it “Tonkin Gulf II.”

“They were totally irresponsible to sign a blank check,” he says.

The solution, too, according to Ellsberg, resembles his own approach.

Current government officials who believe Bush is on a “disaster course,” he says, have an obligation to leak secret information that would derail the administration’s policies.

“They should take the documents that would reveal that to the public. They should copy them and put them on the Internet,” he says. “They should take a file drawer of documents and take them over to Capitol Hill, the New York Times and the Associated Press.”

In this case, Ellsberg argues that going public with secret information would be in the best interest of national security—as it was when he leaked the Pentagon Papers in 1971.

“I wish I had done what I did years earlier,” he says. “Don’t do what I did. Don’t wait until the bombs are falling. Think of it now.”

—Staff writer Catherine E. Shoichet can be reached at shoichet@fas.harvard.edu.