Appearing on ABC News' "This Week with George Stephanopoulos" Sunday -- one day before the fifth anniversary of the Sept. 11 attacks -- Kean said despite the $750 billion spent by the United States to fight terrorism, the threat still exists and will likely continue to do so for generations.
"They plan over long periods of time." Kean said. "And it is a generational threat. It's something, unfortunately, our children and maybe even our grandchildren will be dealing with."
Kean also defended ABC's upcoming "The Path to 9/11" -- which has been attacked by former Clinton administration officials for what they say are inaccuracies and distortions of the commission's report -- saying the mini-series will make a contribution to people's understanding of the attacks.
A Republican, Kean was the only commission member consulted for the mini-series, which claims to be based on the commission's report.
"If people blame Bill Clinton (for the Sept. 11 attacks) after seeing this, then the mini-series will have failed," Kean said. "That's wrong and it shouldn't happen."
Jamie Gorelick, a Clinton deputy attorney general and a Democratic member of the commission, said the administration does not distribute the $715 billion based on risk. "I mean, if you don't give the funds out based on risk and you instead give it out on politics or some formula that gives Wyoming more than New York City, you know, you are wasting money," she said.