This could be interpreted in different ways - "We will easily win any fight" or "The attack will help to bring down our evil system."

If the former, don't underestimate them. As an American, let me say that Americans do not know what real pain is. 9/11 was nothing. Given its unstable racial makeup, it would not take much to bring this country to its knees. We have legions of Blacks who would quickly side with ISIS, at least in words, if doing so would give them free reign to rape and loot.

And the US is very vulnerable. Just ponder what could be done here with a single every-so-tiny vile containing Ebola, then "growing it" in some homeless dude no one would miss, extracting the body fluids and mixing it in hundreds of gallons of ice water and then using a small plane or other means of delivery to spray that mix over a large crowd (one that would scatter all over the country before symptoms started and people would know what they had been exposed to) - a Super Bowl, a New Year celebration, etc.

These days, terrorists don't even need nuclear material to kill millions.

And, for just the record here, the cause of all these catastrophes is the genetics of the people we let into the country, which in turn is the result of the bad genetics of the people who hold positions of power, especially those in the media, government and banking sectors. No more lying psychopaths in power (e.g., Clintons, Obama, Jews) nor delusional weakminded fools (e.g., "Dubya" Bush, Lindsay Graham, etc.).