A few terrorists in our midst is inevitable, and rigorous law enforcement will keep them from becoming dangerous.
You have to understand that extremists of all types pop up in our society all the time, but we almost always manage to nab them before they do something horrendous.
Extremism is not monopoloized by Islam.
So, as long as we focus on keeping foreign militants out of our country, and search and arrest the few home grown ones that will pop up from time to tme, we'll be able to avoid the general mayhem that we see in the Middle East. But by not addressing the issue that produces foreign militants and targets them against us, it would be a losing battle to remain within our borders and not deal with that source.
Think about it.