A devoted comic book fan explained to me that the biggest issue with making a good series of films based on Batman is that other than The Joker, most of the villains suck. The Joker is #1 and once he's gone the drop-off to #2 and beyond is huge. Since the end of the Cold War, American foreign policy (and the military-industrial economy) has had the exact same issue.
The USSR was a great Villain. Americans and their elected leaders could turn the USSR into whatever they wanted, and the Soviet leaders were generally dyspeptic enough to confirm our fears. The (second) Bush administration certainly tried to turn al-Qaeda and then Iraq into the same thing but even people who go through the motions of believing it…they have to know. They must know. They have to know in their heart of hearts that despite al-Qaeda's capacity to execute some genuinely horrific attacks, it's just not the same. Discounting the 15-20% of the population who believe literally anything Fox News spits at them, there's no amount of squinting that can make al-Qaeda look like an existential threat to the U.S. (Oddly enough, the same people who claim that argue that Islamic terrorists are cave-dwelling camel fuckers, and the contradiction speaks to how implausible it is to conceive of them as supervillains. But I digress.)
Now we are going through the same song and dance with ISIS and the overwhelming lack of real interest in or attention paid to the current situation is indicative of how serious we perceive their threat. Sure, they can do all of the things that Modern Terrorist magazine recommends for groups with ideological fervor and minimal resources – maximum shock value tactics like execution videos and post-firefight blood and gore images – but let's be serious here. It's fitting that the group sounds like a third-rate Connery era Bond villain because even by the standards of terrorist/paramilitary organizations they're not terribly impressive. Despite the intense effort by the media to hype them into a suitably terrifying nemesis, very few people who aren't Senators from South Carolina or Texas honestly think "ISIS is coming, the end is near." I mean, what is the narrative? It was at least plausible to think that the USSR could (but wouldn't) launch a nuclear sneak attack in our sleep; is anyone putting the kids to bed with dire warnings that ISIS is going to swoop into the suburbs and blow up the three bedroom ranch?
They sure do pose a threat to private security contractors and certain kinds of international aid workers. That'll give the kids nightmares.