Tom Ridge, who was the governor of Pennsylvania on 9/11, was on “Happening Now,” where he remembered the heroes of Flight 93 and responded to the president's ISIS strategy.

The nation's first DHS secretary concluded that hijackers downed the plane on Sept. 11, 2001, as passengers and crew members tried to fight for control of the jet.

Ridge said that if the passengers and crew of the other three planes had the same information that Flight 93 did, they would have responded in the same way.

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“Their country was in crisis, and they were gonna do whatever they could to minimize a potential threat to others. There was a cause in their hearts bigger than themselves,” he said.

Ridge said 9/11 is a good day to remember the resolve of our nation.

“Today we are far more secure, far better prepared. We’ve demonstrated our resiliency, our ability to respond and recover,” he said.

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Still, he said that he believes the threats to the U.S. today are much greater than they were on Sept. 12, 2001.

Ridge also noted that he was “less than impressed” with President Barack Obama’s remarks on ISIS yesterday, and he said there are “too many fiction writers around him.”

Ridge said the threat isn't only from ISIS, but the "global scourge" of Islamic extremist groups around the world.

"We should have responded immediately with airstrikes after the first murder (of James Foley) and doubled it up after the second. We need to send a statement to the Islamic fundamentalists ... that we have a value system and when you kill Americans we're going to respond immediately and aggressively," said Ridge, calling the president's overall plan "decent" but too isolated to only going after ISIS.

Watch more above.