Any state with sufficient laws can enforce exchanges, businesses, etc. to blacklist wallets which have been identified as foreign owned - if there are sanctions

Any state with sufficient laws can enforce exchanges, businesses, etc. to blacklist wallets which have been identified as foreign owned - if there are sanctions / embargos against said country/countries. Of course, there are ways to obfuscate the money trail, but if they start handing out hard prison time and fines, that alone will probably deter most. So while you still have a "bank", so to speak, you're still limited to whom you can do business with.