The NY Daily News lists the roster of terrorists captured on American soil, or American citizens arrested on suspicion of terrorist ties, or conspiracy to commit terrorist acts.
Most of them were captured on American Soil. In other words, they are homegrown jihadis, emigres, and domestic terrorists.
Please take note of what religion the majority on the list tend to follow. Ill give you a hint; it starts with an "I", and they permit you to kill your female children who refuse to marry their first cousins.
It's a good thing we're not at war with that religion, or it's "moderate" practitioners, we're policing our borders and going after the bad guys in Iraq and Afghanistan so that we don't have to fight them here...