That would be true if ISIS planned to land on some American beach somewhere, D-Day style.
But that is not their plan. Terror attacks like the one in Boston, creeping Sharia law (disguised as laws against "hate"), and home-grown conversions...that's their plan.
How many people do you know who will willingly take part in a home grown conversion or submit to Sharia law? How many people do you know who may even know someone else who would do that?
I’ll bet Zero.