Mr. Ruppert, 58 years old, has since moved on to what he believes are more pressing matters: oil and energy. ("I walked away from 9/11 five years ago," he says. "I have nothing to do with the 9/11 truth movement.") He has a new self-published book, "A Presidential Energy Policy: Twenty-five Points Addressing the Siamese Twins of Energy and Money," and a critically acclaimed new movie, "Collapse," in which he is the sole star and commentator.

Directed by documentarian Chris Smith ("American Movie"), the film consists mostly of Mr. Ruppert speaking about the dangers of peak oil and the looming catastrophe that declining oil reserves could bring. The film opens Nov. 6 in New York and on the new video-on-demand channel FilmBuff.

"The power of 'Collapse' is that Ruppert ... never sounds like a crackpot," Entertainment Weekly critic Owen Gleiberman wrote after the movie's Toronto International Film Festival premiere in September. "You may want to dispute him, but more than that you'll want to hear him, because what he says—right or wrong, prophecy or paranoia—takes up residence in your mind."

But as with "Fog of War," the Oscar-winning documentary about former Secretary of Defense Robert S. McNamara, Mr. Ruppert comes across in the film as both authoritative and dubious, leaving the audience open to make its own judgment of the man and his ideas. The Wall Street Journal sat down with Mr. Ruppert to discuss oil, Wall Street and the "imminent collapse of human industrialized civilization."  

Mr. Ruppert: It is not possible to continue infinite consumption and infinite population growth on a finite planet.

WSJ: So what do you believe needs to be done first?

Mr. Ruppert: Two things are critically important: A real worldwide transparent effort to determine how much oil is really left. Screw state secrets. I don't care what the Saudis, Russians, BP or Chavez want to hide. We have to clean up those books just exactly as the same way that we need to clean up the books on Wall Street. Secondly, we need to establish a second strategic petroleum reserve of refined product for state, county and municipal use because I really foresee a serious oil shock coming as soon as this ersatz recovery starts to push up the global GDP and demand for electricity. We have to make sure we have basic services.

WSJ: In no uncertain terms, you discount all alternative fuel options in the film, calling clean coal a contradiction and ethanol a "joke." How can you be so sure?

Mr. Ruppert: With 800 million internal combustion-powered vehicles on the planet and the fact that oil powers 90% of transportation, there is nothing that replaces what oil does. And transportation, of course, is what makes everything work, from shipping products to shipping people. And you cannot plug any alternative technologies into a 2008 GMC SUV or a 747 airplane. One of the things that I've also stressed is how much energy goes into making products: There's seven gallons of oil in every tire, and all plastics, paints and resins are made from oil.

WSJ: Do you think there's a greater chance of things turning around under the Obama administration?

Mr. Ruppert: No, it's not a matter of political party. It's a matter of energy. And money is useless without energy and money has no respect for power or ideology. We have to reconnect with the requirements that we're living on a planet that's falling apart. And we have to maintain some relationship that's separate from the illusory power of money. Clearly, the power in this country is not in Washington, it's in New York, with the Fed and with Wall Street.

WSJ: How do you see Wall Street playing a role?

Mr. Ruppert: Until you change the way money works, you change nothing. The current economic paradigm calls for infinite growth, from fractional reserve banking to compact interest. So Wall Street needs to somehow help us find an economy that works without requiring more and more consumption.

WSJ: You've been called "a purveyor of amazing tales" as well as a crusading investigative journalist. What's your response?

Mr. Ruppert: I have two responses: One is that I don't matter. You can focus on me or not, or you can focus on the likely imminent collapse of human industrialized civilization, and I think that's the more important story. On the other hand, I have been severely mistreated. I have been tied up with legal attacks for five to six years and there's only so many I can take on at a time. So I can take away time from reporting and spend time protecting my reputation. And I just made the tactical decision that getting the message out was more important.

WSJ: There's a great irony revealed in the film where we learn about your own economic collapse. Are you still behind in your rent?

Mr. Ruppert: Yes. But people are stepping up to help. We raised $17,000-$18,000 for the legal defense fund for this absolutely crazy ruling in Oregon. [Orgeon's Bureau of Labor and Industries has ordered Mr. Ruppert to pay damages for an incident of workplace sexual harassment.] So I have a lot of support out there. I'll just do whatever I have to do.