I believe it was recently reported that 159 known terrorists have been caught crossing our border in 2023. How many managed to enter the USA undetected? My guess, 4 or 5 times that number.
With 100 five man teams, I could bring the USA to its knees. Starvation, total chaos, etc. It would not be difficult, and one would only need to target one type of facility across America, at a synchronized time. And in actuality, it would not take that many resources.