Discussing the threat from terror group ISIL with CNN's Wolf Blitzer, former CIA and NSA director Michael Hayden warned that the United States has underestimated terror groups in the past and "at our peril" would we underestimate one again.
Hayden used the example of the 2009 Christmas day bombing attempt, where the U.S. knew al Qaeda was "up to something", "we just didn't nail that it was a Nigerian in an airplane over Michigan."
Of ISIL, Hayden said, "This threat is coming, and at our peril, we underestimate it or think that it is somewhere in the distant future."
Hayden recommended targeted assassinations, "Not just in retaliation, Wolf. Not just as punishment. We've got take these folks on to prevent them from doing these kinds of things to American citizens."
"My view is that is where we are heading. My view is that is where we need to be," said Hayden.