Yeah, Dutch Elm disease didn't stop at the State lines, either. Nor did Japanese beetles, Gypsy moths or any other foreign insect infestations.
As I'm sure dewey is aware (and should all Minnesotans), we have a lot to lose with EAB. I've heard estimates as high as 3-4 million trees. Slowing the spread by quarantine or any other practical means aids a slower decline and hopefully, we can replant against some of the loss.
AFAIC, we can just bromide every ship from an Asian port. I once unpacked a dining room table from Thailand for a customer. My efforts there stopped when I discovered a spider as big as my hand living under the top.