Battling Terror, Chertoff Felt 'Invisible Burden'
Outgoing Homeland Security Chief Felt Dread of Getting 'The Call' at Any Time
Chertoff added there also is evidence that terrorists are constantly attempting to get into the United States.
"Every month, I get a report from our border authorities about people who are stopped" as they attempt to enter, he said.
Though it's somewhat rare, he said some are stopped "based on what they have in their laptop or what they have in their luggage or based on what we know about them, people who are dangerous, who are coming in either with a plan or a recipe to build an improvised explosive device, or people who we know have affiliations with terrorist groups.
"Fortunately, we have stopped them at the border and that's what protects this country," he added.
Though he wouldn't say how many individuals are stopped for such reasons, he said, "it's certainly a number that would concern me if we stopped doing what we are doing."
Chertoff said progress has been made in fighting the war on terror and strengthening the country's vulnerabilities. He does not believe another 9/11-scale operation aimed at aviation would be successful, but acknowledged some areas remain vulnerable -- such as mass transit, shopping centers, restaurants -- the kind of places targeted in the recent Mumbai attacks.
This war, Chertoff said, is far from over.
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