True. But if the system is implemented by a country this could be implemented using the law system and insurances.
For example, when each transaction is done, both parties might keep a cryptographic proof which they are required to submit once they are online again.
Failing to submit could result in a small fine (to encourage submission) and double spending which can then be detected could result in a large fine (or even a prison sentence), for example.
There is, perhaps, a privacy issue, just like with blockchain. But it's not more of an issue than online transactions.
For example, when each transaction is done, both parties might keep a cryptographic proof which they are required to submit once they are online again.
Failing to submit could result in a small fine (to encourage submission) and double spending which can then be detected could result in a large fine (or even a prison sentence), for example.
There is, perhaps, a privacy issue, just like with blockchain. But it's not more of an issue than online transactions.