If there's merrit to that theory... Probably won't take over a nation, but cause a bunch of havoc and be a distraction or a reason for more gov overreach and "security" for your protection measures.
Discussion
IMO its an utterly laughable concept that has been promoted in one way or another for a very long time. This ISIS version has been fear porned since Obama was in office.
Bingo.
Not taking on the Nation, the Nation will take care of it once the needed false flag was seeded.
Of course it won't be ISIS but rather some crypto agents disguised with confederated flags and Swastikas.
Just look what is happening in Europe right now, undercover agents or gullible deplorables stage Quran burnings to stiffle race wars Christianity vs Islam, while the real enemy coordinates from behind the curtain.
Ya'll worry too much about scary nothings. Like I said, this has been part of the fear porn loop quite some time. The exact same script. Since Obama was president. They want you living in fear. And if something gonna be the nazi angle, they sure as shit aint using brown people coming over the border. Thats patently absurd.