CNN's John Roberts talked with Richard Clarke about his new book, "Your Government Failed You: Breaking the Cycle of National Security Disasters."

Clarke's book looks at a broken system that allows National Security disasters to happen over and over again. Clarke believes that a new President alone cannot fix the problem. Clark told CNN, "The system is broken, and the president alone, no matter how good that President is, the President alone can't fix it unless the system is changed."

Of the remaining candidates, Clarke said that Obama has put the most focus on changing the current system. "I think they have all talked about some of the changes necessary. I think Senator Obama has spent more time talking about the need for structural changes because if you don't change the system, if you only change the President, the kinds of mistakes we've had in intelligence and global warming and cyber security, homeland security, terrorism, will continue."

Clarke told CNN that not destroying Al Qaeda and not capturing or killing Osama bin Laden were the biggest post-9/11 failures of the Bush Administration. Clark said that Iraq became more important to the Bush Administration than the destruction of Al Qaeda.

"U.S. intelligence says that Al Qaeda is now stronger than it has been since 2003 and is training terrorists to go out around the world and commit attacks again. We should have kept our eye on the ball. We should have gone after bin Laden and Al Qaeda, destroyed it entirely, and we didn't. We paid attention for about six months, and then we went off to Iraq."

This video is from CNN's American Morning, broadcast May 28, 2008.

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