It's trivial to block IP addresses listed as being somewhere else. That doesn't block people in other jurisdictions from using a US IP address, either by renting or compromising one in the US or having administrative control over one somewhere else and then setting its metadata to whatever they want.
That's not how you get to high trust, since it requires the opposite -- you'd have to ID everyone and ban VPNs and restrict access to general purpose computers lest any fall under the control of a dastardly foreigner etc.
You can't build a high trust society inside of a police state because a high trust society is one where people do the right thing when no one is holding a gun to their head and a police state is holding a gun to your head.
Residential proxy. Most cloud providers are blocked or already on reputation watch lists.
A few thousand people downloading a “free vpn” app on their phone is all you need to be back up and running. They get a useful vpn in exchange for letting others borrow their IP.